This lesson focuses on the observation of properties and the classification of objects to build ideas about variables. Learners compare buttons to identify similarities and differences. In addition, learners are introduced to Venn Diagrams by reading "The Elves and the Shoemaker" and sorting their shoes in a giant diagram.

This unit consists of four lessons in which students explore several meanings and representations of multiplication, including number lines, sets, arrays, and balance beams. They also learn about the commutative property of multiplication, the results of multiplying by 1 and by 0, and the inverse property of multiplication. Students write story problems and create pictographs. The unit includes activity sheets, assessment ideas, links to related applets, reflective questions for students and teachers, extensions and a bibliography of children's literature with a multiplication focus.

In this data analysis activity students investigate data in connection with recyclable materials and develop plans to help the environment. Students collect data about aluminum can usage and graph that data in a line plot. The lesson includes student worksheet and extension suggestions.

In this 5-lesson unit primary students identify attributes of buttons and other objects in their classrooms. Throughout the unit students learn to collect data about objects, display the data (Venn diagrams, pictographs, and bar graphs), and analyze the data to determine what this tells us about buttons and/or other objects. Each of the five lesson plans includes necessary student/class worksheets, questions for students, extension ideas, and assessment ideas. Lessons 2 and 3 reference stories that are an important part of the skill development: "The Button Box" by Margarette Reid and "The Elves and the Shoemaker" story.

In this two-lesson unit, students will "use estimation and measurement skills to determine the ratio of circumference to diameter and explore the meaning of pi. Students will discover the circumference and area formulas based on their investigations." (from NCTM's Illuminations)

In this math activity, learners explore the history of the Stomachion (an ancient tangram-type puzzle), use the pieces to create other figures, learn about symmetry and transformations, and investigate the areas of the pieces. The Stomachion, believed to have been created by Archimedes, consists of 14 pieces cut from a square, which can be rearranged to form other interesting shapes.

This two-lesson unit from Illuminations, exposes students to algebra, measurement, and data analysis concepts and the major theme of analyzing change. In the first lesson, students measure the heights of classmates and older students and construct a table of height and age data to compare them. The second lesson's instructional goal is to understand how change in one variable, age, can relate to change in a second variable, height. Instructional plan, questions for the students, assessment options, extensions, and teacher reflections are given.

In this lesson students use a rule of thumb about the weight of babies to practice doubling and halving numbers. They complete an organized table and compare data using vertical and horizontal double bar graphs. The lesson includes a student activity sheet and extension ideas.

In this lesson plan students conduct a survey of ten students, collect data in a tally chart, and then display and analyze the results in a bar graph. In the analysis students must compare numbers, add, and subtract using the data in the bar graph to generate questions as well as answer them. The lesson plan includes a graph template, a link to an interactive graphing tool, extension questions, and a fact family sheet to show the related facts from their graph analysis.

The consideration of cord length is very important in a bungee jump‰ŰÓtoo short, and the jumper doesn't get much of a thrill; too long, and ouch! In this lesson, students model a bungee jump using a Barbieĺ¨ doll and rubber bands. The distance to which the doll will fall is directly proportional to the number of rubber bands, so this context is used to examine linear functions.

In this math activity, learners are challenged to create aluminum foil boats that will hold plastic bears until the boats sink. The lesson serves as a fun, hands-on way to collect data. Data from two attempts is collected and used to make two class box-and-whisker plots with some surprising results. This lesson guide includes questions for learners, assessment options, extensions, and reflection questions.

In this 8-lesson unit students use buttons to explore logical and numerical relationships that form the conceptual basis for understanding addition and subtraction operations. Topics include counting, ordinal numbers (and relative position), classification (attributes), relationships between numbers, addition of sets, commutativity of addition, sums to 10, fact families (including subtraction), three models of subtraction ("take away", comparative, missing addend), and bar graphs. Includes student activity sheets and a link to an online graphing applet.

In this 8-lesson unit students use buttons to explore logical and numerical relationships that form the conceptual basis for understanding addition and subtraction operations. Topics include counting, ordinal numbers (and relative position), classification (attributes), relationships between numbers, addition of sets, commutativity of addition, sums to 10, fact families (including subtraction), three models of subtraction ("take away", comparative, missing addend), and bar graphs. Includes student activity sheets and a link to an online graphing applet.

In this Illuminations lesson plan students explore the use of variables as they solve for the weights of objects using information presented in pictures. Learners model situations that involve adding and subtracting whole numbers, using objects, pictures, and symbols. A student activity sheet is available and downloadable (pdf).

This interactive applet introduces students to the topic of combinations, a basic concept in probability. Users create combinations of shirts and pants to determine the total number of possible outfits. They may simply explore by placing the clothes on Bobbie, or make a guess and then test it. The number of shirt and pants choices is customizable. An optional voice provides prompts and feedback.

This Flash tool allows students to make a box plot of their data, using up to four categories of their own choosing, or using one of the data sets provided. The tool will plot all the data together, or break it out by category. Students can set a multiple of the Interquartile Range to be the Extreme Range, and exclude that data from the graph if they wish. Associated lessons (free) and a Mathematics Assessment Sampler (for purchase) are linked at the right side of the page.

This 3 lesson instructional unit helps students investigate many different aspects of triangles including basic properties of triangles, building other shapes from triangles, the dependence of the third side length on the other two (Triangle Inequality Theorem), and the Sierpinski Triangle fractal. The lesson includes student activity sheets and links to interactive applets.

This lesson helps students develop spatial visualization skills and geometric understanding by exploring the different nets that can be folded into a cube. The lesson is placed in the context of a young woman who is trying to build a jewelry box. The lesson provides an activity sheet, a link to a helpful applet (Cube Nets, cataloged separately), questions for students and teachers, and ideas for assessment and extensions.

This 3 lesson instructional unit helps students investigate many different aspects of triangles including basic properties of triangles, building other shapes from triangles, the dependence of the third side length on the other two (Triangle Inequality Theorem), and the Sierpinski Triangle fractal. The lesson includes student activity sheets and links to interactive applets.

Using the story "The Celebrated Jumping Frog of Calaveras County" by Mark Twain, learners simulate a jumping-frog contest and determine the distances "jumped." Learners record the distance of individual jumps in centimeters and determine the total distance jumped (the sum of the three separate jumps) and the official distance (the straight-line distance from the starting line to the end of the frog's third jump). Learners compare the range and median of the total distances with those of the official distances of the group.

This Java applet activity allows students to explore the various situations described in "The Chairs Around the Table" lesson (cataloged separately). The user can select Exploration mode, in which the number of chairs needed for a particular arrangement of tables is displayed; or Guess, in which the user is able to construct an arrangement and then predict the number of chairs. There are two types of tables to choose from and two different table arrangements. Instructions and exploration question are provide.

In this lesson from Illuminations, students explore and discover linear relationships. Linear patterns are identified, extended and described verbally, numerically and algebraically through three investigations. Using manipulatives and the linked applet, "Chairs", learners determine the number of chairs needed when the number of tables is known, and vice versa. Instructional plan, questions for the students, assessment options, extensions and teacher reflections are provided.

An applet for students to use in exploring the area and circumference of a circle in relation to its radius and diameter. When the radius is changed, the other measures automatically change and are shown on a board. Most importantly, the ratio between any pair of these measures can be shown.

This applet allows students to investigate the relationships between the area and circumference of a circle and its radius and diameter. There are three sections to the site: Intro, Investigation, and Problems. In the Intro section, students can manipulate the size of a circle and see how the radius, diameter, and circumference are affected. Students can also play movie clip to visually see how these measurements are related. The Investigation section allows students to collect data points by dragging the circle radius to various lengths, and adding and recording the data to a table which records the radius, diameter, circumference and area. Clicking on the x/y button allows students to examine the relationship between any two measures. Clicking on the graph button will take students to a graph of the data. They can plot any of the four measures on the x-axis against any of the four measures on the y-axis. The Problems section contains questions for students to solve and record their answers in the correct unit.

In this data collection and analysis activity students investigate data in connection with recyclable materials and develop plans to help the environment. This activity requires students to keep track of their own paper use for a week, graph the data with a line graph and then interpret their results with a partner. The lesson includes student worksheets and extension suggestions.

This lesson develops number skills, understanding of coin values, and the concept of equivalence. Students use coin blocks, concrete representations of the value of coins (pennies, nickels, dimes, and quarters), to compose and decompose values up to a dollar. The resource includes a 3-minute video for teachers on how to build the coin blocks prior to the lesson. An interactive game, Coin Box, provides additional practice for students and is cataloged separately.

In this Flash game, students may use a variety of activities to practice counting, collecting, exchanging, and making change for coins. Coin representations may show their amounts or not; coins may also be represented by coin tiles on a 10x10 grid, to help visualize their values. The five activities are: count, in which students determine the value of a given set of coins; collect, in which students choose coins to represent a given value; exchange, in which students use the smallest number of coins to represent a given value; change from coins, in which students are given a set of coins and asked how much change would be for a dollar (essentially counting up); and change from value, in which students are given a price owed (from a dollar) and asked to make change. There is a "bank" at the lower left side of the applet in which coins may be exchanged for other coins of the same value.

This 2-lesson unit focuses on combinations, a subject related to probability. Students develop strategies for discovering all the possible combinations in two given situations. They learn to collect and organize data and then use the results to generalize methods for determining possible combinations. They discuss how the number of possible outcomes is affected by decisions about the order of choices, or whether choices may be repeated. The unit includes student activity sheets, questions and extensions for students, and a link to an interactive applet.

In this lesson plan students learn to create bar graphs using unifix cubes, translate this representation to graph paper, and then compare the data that has been collected and displayed. Students are encouraged to make up their own questions about the data (favorite juice) and to practice with multiple sets of data. Sample questions for students and extension ideas are included. The lesson contains links to a PDF of graph paper and the Bar Grapher tool which is cataloged separately in this database.

In this 6-lesson unit, students explore 5 models of subtraction (counting, sets, number line, balanced equations, and inverse of addition) using connecting cubes. The lesson activities focus on the comparative mode of subtraction as children investigate the relationship between addition and subtraction, write story problems in which comparison is required, and practice the subtraction facts. The lessons include printable student activity sheets, a bibliography of children's counting books, questions for student discussion and teacher reflection, assessment options, extensions, and links to online applets (cataloged separately).

This familiar game can be played by one or two players taking turns. Players choose to match equivalent representations of numbers, shapes, fractions, or multiplication facts. The game can be played in clear pane mode, or for added challenge, with the windows closed.

This unit contains two lessons which help students develop number sense through activities involving collection, representation, and analysis of data. Students also practice reading and writing large numbers and develop estimation skills. In Lesson 1, Every Breath You Take, students estimate the number of breaths taken during a specified time, experiment, and display real-life data. In Lesson 2, Making Your First Millions, students develop the concept of a million by working with smaller numerical units, such as blocks of 10 or 100, and then expanding the idea by multiplication or repeated addition. They analyze situations and identify patterns that will enable them to develop the concept of large numbers. Each lesson includes student activity sheets, an instructional plan, and extensions.

This place value and problem solving lesson focuses on forming 3-digit address numbers to meet specific requirement. The lesson provides an opportunity for learners to use the problem-solving strategies of looking for patterns and establishing an organized list. Students also learn that careful reading of information and understanding of mathematical language are important to finding appropriate solutions.

This unit of four lessons highlights different aspects of students’ understanding and use of patterns as they analyze relationships and make predictions, as discussed in the Algebra Standard. In this cluster of activities, students use two interactive math applets (both catalogued separately) to learn about repeating and growing patterns. In the first part, students explore a two-square pattern unit and in the second part, students investigate repeating patterns with pattern units of three, four, and five squares. In Part 3, students analyze repeating patterns of colored cubes and lastly in Part 4, students create growing patterns of colored cubes and compare them to repeating patterns.

This interactive applet helps students develop spatial visualization skills and geometric understanding in both two and three dimensions. From an array of possible nets, students try to select the ones that actually fold to a cube. The applet supports the lesson Building a Box (cataloged separately). An animation that shows one net being folded is included.

In this lesson, students will use formulas they have explored for the volume of a cylinder and convert them into the same volume for rectangular prisms while trying to minimize the surface area. Various real world cylindrical objects will be measured and converted into a prism to hold the same volume. As an extension, students may design and create a rectangular prism container according to their dimensions to compare and contrast with the cylinder.

Students use this interactive tool to explore the connections between data sets and their representations in charts and graphs. Enter data in a table (1 to 6 columns, unlimited rows), and preview or print bar graphs, line graphs, pie charts, and pictographs. Students can select which set(s) of data to display in each graph, and compare the effects of different representations of the same data. Instructions and exploration questions are provided using the expandable "+" signs above the tool.

This project-based unit on statistics provides an opportunity for problem solving through real-world data collection and analysis. Students follow the seven- step "Elementary Mathematics Research Model" by identifying a research question, predicting the answer, and conducting research to test their hypothesis. Students use the mean, mode and median to analyze their data and use graphs to represent their findings so they can draw and justify conclusions. The lesson plan includes examples, questions for students, and possible assessment and extension ideas.

Okta challenges you to a duel! That crazy octopus wants to play you in a game where the first person to choose cards with a specified sum wins. You can choose how many cards, what types of numbers, and Okta's level of strategy.

This lesson plan introduces the game Deep Sea Duel, which develops students' operation skills and strategic thinking, and can be played online or with cards. After playing several variations of the game, students attempt to identify a winning strategy and compare the game to other familiar games. Variations include whole numbers, decimals, fractions, exponents, and words. The lesson includes printable cards and a student worksheet, questions for student discussion and teacher reflection, assessment options, and extensions. The online game and the cited article are cataloged separately.

In this 6-lesson unit, students use dominoes to explore four models of addition: counting, number line, sets, and balanced equations. They learn about the commutative property, the relation between addition and subtraction, the result of adding 0, and the concept of doubles. Students write story problems which involve the operation of addition and begin to memorize the addition facts. They represent addition in pictures. The various models of addition help students develop a rich conceptual schema for addition. Included are a Bibliography of Counting Books, student materials, questions for student and teacher reflection, assessment and extension ideas. [Suggestion: Use the alternate applet, Pan Balance - Numbers, listed as a Related Resource, rather than Pan Balance - Shapes, in Lesson 4.]

In this lesson plan from NCTM Illuminations students learn to add fractions with like and unlike denominators to make a sum of one. The lesson plan includes two games utilizing fraction cards (PDF) and a fraction bar chart (PDF), and an online game through Calculation Nation which is cataloged separately.

In this 7- lesson unit students use tallies, pictographs, bar graphs, line plots, circle graphs, box-and-whisker plots, and glyphs to collect and display data about healthy eating. The unit includes lessons in which two sets of data are being compared and data sets are being analyzed for measures of central tendency (mean, median, mode). Learning objectives, materials, student questions, extensions, teacher reflections, and links to create graphs virtually are included.

In this lesson, students are presented with a design challenge. Students make arrays to create options for package design for 24 eggs. Students work together to find the arrays and respond to the egg company.  

In this interactive activity a user identifies two pairs of equivalent fractions for a given random fraction or one of the player's own and the user creates their representations by dividing and shading either a square or circular region. The fractions are shown as locations on the number line and their equivalency is demonstrated when they are at the same point. The user has the ability to construct a table of equivalent fractions. Instructions and exploration questions are given.

In this math activity, learners are presented with a problem: two bowls are suspended from the ceiling by springs. One bowl is lower than the other. In one bowl, you can only place marbles; in the other bowl, you can only place bingo chips. Learners investigate how many items must be placed in each bowl so that the heights of the bowls are the same, and in doing so, solve a system of linear equations. This lesson guide includes questions for learners, assessment options, extensions, and reflection questions.

This Illuminations activity focuses on making predictions and the collection and analysis of data by having students take their pulse after different exercises. All individual data is collected in a classroom chart where the results are interpreted and conclusions drawn. The lesson includes a student worksheet and extension questions.

In this unit, students use online pan balances to study equality, order of operations, numerical and variable expressions, and other key algebraic concepts. Lessons focus on balancing shapes to study equality and equivalence; balancing algebraic understanding, to explore simplifying expressions; and balancing algebra, to determine if algebraic expressions are equal.

This lesson plan provides the teacher with an activity for introducing the game Krypto, which helps to develop number sense, computational skill, and an understanding of the order of operations. Players are given five number cards. They combine them, using the standard arithmetic operations, to create a target number. As students investigate the game, they develop strategies for finding solutions efficiently. The plan includes learning objectives, materials needed, questions to ask students, assessment options, extensions, teacher self-reflection questions, and a link to the online version, Primary Krypto, (catalogued separately).

The rules of Krypto are amazingly simpleäóîcombine five numbers using the standard arithmetic operations to create a target number. Finding a solution to one of the more than 3 million possible combinations can be quite a challenge, but learners love it. This game helps to develop number sense, computational skill, and an understanding of the order of operations. Play this game online or use a deck of Krypto cards.

In this math lesson, learners examine pennies and dimes and model subtraction as they listen to a childrenäóťs book ("Alexander Who Used to Be Rich Last Sunday" by Judith Viorst). Learners model amounts to 60 cents with coins, use coin rubbings of pennies and dimes, and make a chart comparing the two coins.

In this two-day lesson plan students collect, display, and analyze data about the eye color of their classmates. On day one, students display the eye color data in a pictograph and discuss what questions can and cannot be answered using this graph. On the second day of the lesson, data from a partner class is used to create a second pictograph. Students then compare these graphs and determine what questions can and cannot be answered using these two graphs. Questions and extension suggestions (including making a circle graph to represent data) are also included in the lesson plan.

In this lesson, students first create factor posters for a variety of different numbers that will be displayed in the classroom to be utilized as a resource throughout the school year. They make discoveries about factors using color tiles, represent their discoveries using graph paper, and display their information on poster board as find factors of an assigned number. The plan includes a list of materials, questions, assessment options, and extensions.

This is an interactive applet game exercises a student's factoring ability. A student can play against the computer or against a friend on grids containing the numbers 1-30, 1-49, or 1-100. Each player in turn chooses a number from the board, and then the opponent claims all of its remaining proper factors. A player's score is the sum of all the numbers and factors she/he has chosen. When there are no numbers remaining with unclaimed factors, the game ends and the player with the greater total is the winner.

An online, interactive, multimedia math investigation. The Factor Game engages students in a friendly contest in which winning strategies involve distinguishing between numbers with many factors and numbers with few factors. Students are then guided through an analysis of game strategies and introduced to the definitions of prime and composite numbers.

When students play the Factor Trail game, they have to identify the factors of a number to earn points. Built into this game is cooperative learning Š—” students check one another's work before points are awarded. The score sheet used for this game provides a built-in assessment tool that teachers can use to check their students' understanding.

In this math game, learners identify the factors of a number to earn points. Although practicing a mundane skill, learners enjoy the work because of the game scenario. Built into this game is cooperative learning--learners check one another's work before points are awarded. This lesson guide includes questions for learners, assessment options, extensions, and reflection questions.

This interactive applet allows a student to visually explore the concept of factors by creating different rectangular arrays for a number. The user constructs the array by clicking and dragging on a grid. The length and width of the array are factors of the number. A student can elect an option of a randomly selected number or the student selects his own number between 2 and 50. Exploration questions are included to promote student discovery of mathematical concepts with factors.

Through this four part lesson students develop an understanding of the relationship between area and perimeter. The lesson involves students making human rectangles, exploring geoboard connections, playing perimeter war, and playing Square Off from Calculation Nation. The lesson plan includes all data collection worksheets, games pieces, link to Calculation Nation, extension and assessment ideas.

In this primary grades Illuminations lesson, students identify figures on a football field. They look for both congruent and similar figures, and they consider figures that are the same but that occur in a different orientation because of translation, rotation, or reflection. The lesson includes a student worksheet and discussion questions.

Students can use this interactive Flash applet to practice subitizing and counting groups of objects, to understand the importance of 5 in our base-10 number system, and to learn basic addition facts. In the four included games students construct groups of 5 objects, add groups of objects within 10, and identify and record numbers within 10. Auditory prompts support students with limited reading ability.

This unit of four lessons from NCTM's Illuminations lets students conduct surveys and represent data in a variety of ways. They also find and compare measures of center. The lessons center around a food court, where students create and use menus in a meaningful way. Topics covered include bar graphs, line plots, and pictographs, measures of center, and probability of events. Individual lessons link to related tools where appropriate, and include questions for students, assessment options, and teacher reflection questions.

In this measurement lesson plan students use their estimation and reasoning skills to develop benchmarks for an ounce and a pound. Students test the accuracy of their estimates using a scale and give themselves a score based on how close they came to the desired weight (an ounce or a pound). This lesson plan includes a student data collection worksheet (PDF).

Using this tool, students build these classic fractals: the Koch snowflake, a fractal tree, a reduced square, and the Sierpinksi triangle. As these shapes grow and change using an iterative process, students can observe patterns in the images created and in the table of values as the fractals progress through several stages.

In this lesson plan students use fraction bars to explore and compare the sizes of fractions. The lesson includes an activity sheet, answer key, guiding questions and prompts, assessment options and extensions, and a link to Fraction Feud, an interactive game (cataloged separately and listed as a related resource).

This applet allows students to individually practice working with relationships among fractions and ways of combining fractions. It is an online, one person game, with immediate feedback on incorrect moves. All instructions for this fun visual game are included and illustrated.

Explore different representations for fractions. This applet allows students to create a fraction,then see it as a visual model, and as percent and decimal equivalents. They can choose the model to be a circle, a rectangle, or a set model. Intended for the young learner, this version restricts the numerator to values from 0 to 20, and the denominator to benchmark values of 1, 2, 4, 5, 8, 10 and 20.

This lesson fosters a student's conceptual fraction sense with proper fractions, improper fractions, and mixed numbers by placing thirty fraction cards in order between given whole numbers on a number line clothesline. Users will visually identify that all proper fractions are grouped between zero and one, and that improper fractions or mixed numbers are all grouped above one. Users also play an estimation game with groups using the same principle. Instructional plan, questions for the students, assessment options, extensions, and teacher reflections are given.

This lesson initiates the development of skills in collecting and recording data. First, learners read "Freckle Juice" by Judy Blume. Then, learners collect data about a partner's face and tally the data from the whole class. They learn the convention for displaying a set of five using tally marks. Then, learners create a pictograph and pose and answer questions about the data set. This lesson guide includes questions for learners, assessment options, extensions, and reflection questions.

In this five lesson unit with overview from Illuminations, student activities explore relationships among fractions through work with the length model. Students construct fraction strips and use fraction bars throughout the unit to make sense of basic fraction concepts, to compare fractions and order fractions and to work with equivalency in fractions. Specific learning objectives, a material list, an instructional plan, questions for the students, assessment options, extensions, and teacher reflections are given for each lesson.

This unit from Illuminations consists of five lessons designed to help students understand fractions when they are represented as a part of a region. Learners investigate relationships between parts and wholes, the relative value of the fraction based on the pattern block shape and equivalency while working with physical and/or virtual pattern blocks. Instructional plan, questions for the students, assessment options, extensions, and teacher reflections are given for each lesson.

In this math activity, learners practice decision-making skills leading to a better understanding of choice versus chance and building the foundation of mathematical probability. SKUNK is a variation on a dice game also known as "pig" or "hold'em." The object of SKUNK is to accumulate points by rolling dice. Points are accumulated by making several "good" rolls in a row but choosing to stop before a "bad" roll comes and wipes out all the points. SKUNK can be played by groups, by the whole class at once, or by individuals.

This tool allows you to learn about various geometric solids and their properties. You can manipulate each solid, seeing it from every angle. You can also color each shape to explore the number of faces, edges, and vertices. With that information, you are challenged to investigate the following question: For any polyhedron, what is the relationship between the number of faces, vertices, and edges?

Explore geometric solids and their properties with these interactive tools, beginning with an introduction to the faces of basic polyhedra; counting the number of faces, edges, and corners (vertices) in various solids; discovering Euler's Formula; constructing physical models of geometric solids; and identifying which geometric solids can be made from given nets.

In this Illumination activity, students act as reporters at the Super Bowl. Students study four pictures of things that they would typically find at a football game: players, a scoreboard, a crowd, and a concession stand. Students are asked to create problem situations that correspond to their interpretation of each of the pictures. The lesson includes a student worksheet and extension questions.

This interactive lesson encourages young students to solve problems by estimating angles and distances. They use an applet to give LOGO-like commands, e.g. forward (length), turn (right or left) to make a path that moves a turtle to a pond. Students can create a Path 1 and Path 2 and try to minimize the total path length. There is a newer applet (Turtle Pond, cataloged separately) that allows for adding or editing the commands and a choice of right angles only, or angles in multiples of 15 degrees. The lesson provides suggestions for implementation and discussion questions.

In this lesson plan students gather data about the items that they would normally throw in the trash. Once students collect the data they create a bar graph to display the number and kinds of materials they discard and then use this data to create a plan to reduce garbage and help the environment. The lesson plan includes an activity sheet (PDF) for graphing data and extension activity suggestions.

This lesson begins with a basic visual used in many textbooks: a 10 ля 10 grid as a model for demonstrating percent as "parts per hundred" with a worksheet of these grids to print for each student. The lesson goes on to extend the model to solve various percentage problems. Especially valuable is the illustration of each problem and the thorough explanation that accompanies it.

This intereactive Flash applet helps children learn grouping, tally marks, place value, addition, and subtraction. Students help the alien spaceship move cows into corrals by counting by 5s and 10s. They also can apply those grouping skills to practice adding and subtracting two-digit numbers with regrouping. Audio cues and prompts reinforce the user's actions and facilitate counting and the development of math language.

This lesson, from Illuminations, gives students practice in measurement and in displaying and interpreting data through box-and-whisker plots. Students may draw the plots themselves or use the online Box Plotter tool. Learning objectives, materials, student questions, extensions, teacher reflections, and NCTM Standards alignment are provided.