This google slide show will be used by grade 2 teachers with their students as a numeracy routine. Students should be given time to notice and wonder about each slide. Focus is on composing and decomposing numbers as well as discussion of addition and subtraction strategies. Steve Wyborney is the original creator.

This google slide presentation is a collection of Steve Wyborney's SPLAT! routine, arranged in a sequence by weeks for use with grade 3. Students will work on subitizing, finding missing addends, and creating equations to represent their thinking.

In this 25-day module of Grade 4, students extend their work with whole numbers.  They begin with large numbers using familiar units (hundreds and thousands) and develop their understanding of millions by building knowledge of the pattern of times ten in the base ten system on the place value chart (4.NBT.1).  They recognize that each sequence of three digits is read as hundreds, tens, and ones followed by the naming of the corresponding base thousand unit (thousand, million, billion).

Find the rest of the EngageNY Mathematics resources at https://archive.org/details/engageny-mathematics.

In Module 3, students' understanding of addition and subtraction of fractions extends from earlier work with fraction equivalence and decimals. This module marks a significant shift away from the elementary grades' centrality of base ten units to the study and use of the full set of fractional units from Grade 5 forward, especially as applied to algebra.

Find the rest of the EngageNY Mathematics resources at https://archive.org/details/engageny-mathematics.

Module 4 marks the next exciting step in math for kindergartners, addition and subtraction! They begin to harness their practiced counting abilities, knowledge of the value of numbers, and work with embedded numbers to reason about and solve addition and subtraction expressions and equations. In Topics A and B, decomposition and composition are taught simultaneously using the number bond model so that students begin to understand the relationship between parts and wholes before moving into formal work with addition and subtraction in the rest of the module.

Find the rest of the EngageNY Mathematics resources at https://archive.org/details/engageny-mathematics.

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.

The activities in this 6-lesson unit use fish-shaped crackers to help students develop their understanding of comparative subtraction by exploring five meanings of subtraction (counting, sets, number line, balance, and inverse of addition). Students investigate properties of subtraction, represent subtraction with objects and pictures, record subtraction with vertical notation and equations, create and solve problems, and carry out missing addend activities. Lessons include questions for student discussion and teacher reflection, extensions, printable student sheets, assessment options, and links to online applets.

This interactive Flash applet helps students develop number sense and fluency with addition and subtraction facts within 10. Okta hides some bubbles under a shell, and then either adds more bubbles or takes some away. Students determine how many bubbles are left under the shell. Users can choose a specific one-digit starting number or let the applet choose randomly. Users can select addition, subtraction or both.

Students read lists of the key words that direct them to add, subtract, multiply, or divide. They then identify them in an interactive exercise.

KenKen is a puzzle game that helps students develop whole number calculation skills, logical thinking and perseverance. Users complete the interactive grid with the digits 1-4 (or 1-6) so that each digit appears exactly once in each row or column, while also forming a target number using a specific operation. This page provides four new KenKen puzzles daily with a range of difficulty. Each puzzle includes instructions, rules, and a print option.

How much shorter is Lil' Sister than Big Sister? This 3 Act Task by Graham Fletcher begins with picture of two sisters standing back to back. First students make observations and estimates to begin determine how much shorter the little sister is to the bigger sister. Students can then use images of each sister along with a measuring tool of interlocking cubes to determine the height of each sister. Lastly, students will find the difference between the girls' two heights. Students are estimating, measuring, adding, and subtracting to determine how much shorter the little sister is than the big sister.

In this unit plan, primary learners explore the five models of subtraction (counting, sets, number line, balanced equations, and inverse of addition) using concrete (links), pictorial, and verbal representations to develop an understanding of symbolic notations. Students also investigate fact families, including those where one addend is 0 and where the addends are alike and also learn that the order (commutative) property) does not hold for subtraction. A brief bibliography of related books for children is provided. Instead of using hands on manipulatives and balances, links to Java applets: Pan Balance-Shapes and Pan Balance-Numbers ( both cataloged separately) are included. Instructional plan, questions for the students, assessment options, extensions,and teacher reflections are given for each lesson as well as links to down load all student resources.

In this 6-lesson unit students use pasta shapes to explore the take away model of subtraction in several different contexts (counting, sets, number line, balanced equations, and inverse of addition). They decompose numbers, explore the zero property, act out subtraction situations with objects and pictures, record differences with vertical and in horizontal notation, create fact families, find differences with a calculator, and compose and solve problems involving subtraction. The lessons include student activity sheets (pdf), questions for student discussion and teacher reflection, assessment options, and links to online applets.

The purpose of this task is for students to find different pairs of numbers that sum to 9.

This task requires students to study the make-a-ten strategy that they should already know and use intuitively. In this strategy, knowledge of which sums make a ten, together with some of the properties of addition and subtraction, are used to evaluate sums which are larger than 10.

Making a 10 provides a technique to help students master single digit addition. The task is designed to help students visualize where the 10's are on a single digit addition table and explain why this is so. This knowledge can then be used to help them learn the addition table.

This task provides three types of comparison problems: Those with an unknown difference and two known numbers; those with a known difference and a bigger unknown number; and those with a known difference and smaller unknown number. Students may solve each type using addition or subtraction, although the language in specific problems tends to favor one approach over another.

All the activities in this lesson are addition and subtraction based. It is not designed to introduce addition and subtraction, rather, to supplement and enrich lessons already being taught. This lesson is not designed to be completed in one sitting. It may be done throughout an entire addition and subtraction unit. These activities may be used as starter activities when introducing new math concepts, particularly those that relate to addition and subtraction.