This activity consists of classroom lessons where children observe tree leaves and compare and contrast those leaves leading to an understanding of the terms deciduous and evergreen (and also coniferous). They then use that learning to help them identify the kind of tree based on samples on a chart.

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 task gives students an opportunity to work with exponential functions in a real world context involving continuously compounded interest. They will study how the base of the exponential function impacts its growth rate and use logarithms to solve exponential equations.

The purpose of this task is for students to compare fractions using common numerators and common denominators and to recognize equivalent fractions.

This task is meant to address a common error that students make, namely, that they represent fractions with different wholes when they need to compare them. This task is meant to generate classroom discussion related to comparing fractions. Particularly important is that students understand that when you compare fractions, you implicitly always have the same whole.

This task is appropriate for assessing student's understanding of differences of signed numbers. Because the task asks how many degrees the temperature drops, it is correct to say that "the temperature drops 61.5 degrees." However, some might think that the answer should be that the temperature is "changing -61.5" degrees. Having students write the answer in sentence form will allow teachers to interpret their response in a way that a purely numerical response would not.

The purpose of this task is to foster a classroom discussion that will highlight the difference between multiplicative and additive reasoning.

The purpose of this task is to assess studentsŐ understanding of multiplicative and additive reasoning.

This lab activity is designed to allow students to experience what an increase in mechanical advantage means. Students determine the mechanical advantage of three pulley set-ups. Students also measure the work input and output, then calculate the efficiency. Finally, students determine the relationship between the mechanical advantage and the efficiency of the pulleys.

The purpose of this task is to generate a classroom discussion that helps students synthesize what they have learned about multiplication in previous grades.

This task can be used to either build or assess initial understandings related to rational approximations of irrational numbers.

Students must calculate the volume of a cone in this real world task.

This task provides the opportunity for students to reason about graphs, slopes, and rates without having a scale on the axes or an equation to represent the graphs. Students who prefer to work with specific numbers can write in scales on the axes to help them get started.

The purpose of this task is to help develop students' understanding of addition of fractions; it is intended as an instructional task.

The purpose of the task is for students to compare signed numbers in a real-world context.

The focus of this task is on understanding that fractions, in an explicit context, are fractions of a specific whole. In this problem there are three different wholes: the medium pizza, the large pizza, and the two pizzas taken together.

This is an inquiry where students will be comparing and contrasting two different types of leaves with a partner.

Many students will not know that when comparing two quantities, the percent decrease between the larger and smaller value is not equal to the percent increase between the smaller and larger value. Students would benefit from exploring this phenomenon with a problem that uses smaller values before working on this one.