The purpose of this series of tasks is to build in a natural way from accessible, concrete problems involving volume to a more abstract understanding of volume. In this iteration, we do away with the lines that delineate individual unit cubes (which makes it more abstract) and generalize from cubes to rectangular prisms.

The purpose of this series of tasks is to build in a natural way from accessible, concrete problems involving volume to a more abstract understanding of volume. Here, we are given the volume and are asked to find the height.

The purpose of this series of tasks is to build in a natural way from accessible, concrete problems involving volume to a more abstract understanding of volume. This problem is based on ArchimedesŐ Principle that the volume of an immersed object is equivalent to the volume of the displaced water.

Watch your solution change color as you mix chemicals with water. Then check molarity with the concentration meter. What are all the ways you can change the concentration of your solution? Switch solutes to compare different chemicals and find out how concentrated you can go before you hit saturation!

In this video segment you’ll discover how using concentric circles can help you determine how much paint is needed to cover the deck of a carousel.

This task is designed to give students insight into the effects of translations, rotations, and reflections on geometric figures in the context of showing that two figures are congruent.

Students' first experience with transformations is likely to be with specific shapes like triangles, quadrilaterals, circles, and figures with symmetry. Exhibiting a sequence of transformations that shows that two generic line segments of the same length are congruent is a good way for students to begin thinking about transformations in greater generality.

This task has two goals: first to develop student understanding of rigid motions in the context of demonstrating congruence. Secondly, student knowledge of reflections is refined by considering the notion of orientation in part (b).

The purpose of this task is to have students think about the meaning of multiplying a number by a fraction, and to use this understanding of fraction multiplication to make sense of the commutative property of multiplication in the case of fractions.

The construction of the perpendicular bisector of a line segment is one of the most common in plane geometry and it is undertaken here. In addition to giving students a chance to work with straightedge and compass, the problem uses triangle congruence both to show that the constructed line is perpendicular to AB and to show that it bisects AB.

This task is for instruction purposes. Part (b) is subtle and the solution presented here uses a "dynamic" view of triangles with two side lengths fixed. This helps pave the way toward what students will see later in trigonometry but some guidance will likely be needed in order to get students started on this path.

This short video and interactive assessment activity is designed to teach fourth graders about conversion word problems (english units).

This short video and interactive assessment activity is designed to teach second graders about conversion word problems (english units).

This short video and interactive assessment activity is designed to teach fifth graders about conversion of ounces into pounds and ounces.

This short video and interactive assessment activity is designed to give fifth graders an overview of conversion between units of weight (english units).

This short video and interactive assessment activity is designed to give fourth graders an overview of analog and digital clocks.

This short video and interactive assessment activity is designed to teach second graders about converting coins - two units.

This short video and interactive assessment activity is designed to give fifth graders an overview of conversion between cups, pints, and quarts.

This short video and interactive assessment activity is designed to teach fourth graders about converting pints to cups.

This short video and interactive assessment activity is designed to teach fourth graders about converting gallons to cups.