This animated “Math Shorts” video explains the term additive inverse and provides several examples that demonstrate the concept. In the accompanying classroom activity, students create equations and solve problems that involve adding groups of negative and positive integers that sum to zero. To get the most out of this activity, students should be familiar with plotting positive and negative integers on a number line.

In this video, learn how to use division and place value to convert fractions to decimals. In the accompanying classroom activity, students watch the video to help them learn how to convert a fraction to a decimal using division. Then, they turn their attention to placing rational numbers on a number line. Practicing the placement of these numbers reinforces students’ number sense. It also gives them practice converting among the different representations of a single rational number.

This animated Math Shorts video explains how the distributive
property can help students model and create equivalent expressions. In the
accompanying classroom activity, students play a quick game where they identify
common factors within an expression and work on a series of problems that stretch their
understanding of how to apply the distributive property. While the problems begin with
whole number expressions, they soon work towards algebraic notation, and eventually
develop the idea that ax + bx can be rewritten as x(a + b).

In this Math Shorts video, learn how to solve problems that involve finding unknown angles of various types. In the accompanying classroom activity, students first review supplementary, complementary, vertical, and adjacent angles and then watch the video. Finally, students apply what they’ve learned by writing and solving equations that involve angle measurement, using algebraic notation to represent relationships among angles. To get the most from the lesson, students should be comfortable solving equations in the form ax = b.

In this video, learn how to find the greatest common factor of two numbers. Then, see how this can be used to solve problems with large numbers. In the accompanying classroom activity, students learn to find prime factors using factor trees. They then learn how prime factors, a Venn diagram, and simple multiplication can help them find the greatest common factor of two numbers. The lesson challenges students to find the greatest common factor of increasingly large numbers. It also pushes them to think about how prime factors are the building blocks of composite numbers.

In this video, learn how to use long division to divide large numbers. In the accompanying classroom activity, students learn how to use the standard long division algorithm. They explore alternative ways of thinking about long division by using place value to decompose three-digit numbers into hundreds, tens, and ones, creating three smaller (and less complex) division problems. Students then use these different solution methods in a short partner game.

In this video, learn how ratios, tables, and graphs can help identify proportional relationships. In the accompanying classroom activity, students use a classic mathematical task to improve their understanding of ratios and proportions. After watching the video and having a brief class discussion and review of ratios, students work in pairs to determine which of two punch mixtures tastes more like juice. This set of problems extends students' understanding of ratios while requiring them to use both multiplicative and additive reasoning in their responses.

In this animated ÒMath ShortsÓ video, learn about reflection, one type of movement for geometric shapes. The animation begins by relating the geometric meaning of reflection to its more common understandingÑa mirror imageÑand then displays geometric shapes on a coordinate plane reflecting through the x and y axis. The animation also explains how to ensure that a shape has been correctly reflected and how to record the coordinates of a shape and its reflected image.

In this animated ÒMath ShortsÓ video, learn about rotation,which describes how a geometric shape turns around a point, called the center ofrotation. When a geometric shape rotates on a coordinate plane, it stays exactly
the same distance from the center of rotation whether it rotates a quarter-turn or a full-turn, and whether it rotates clockwise or counter-clockwise. However, even though the shape stays the same as it rotates, its coordinates change.

This animated Math Shorts video explains the term scientific notation and provides several examples in converting extreme numbers to and from scientific notation. It also demonstrates how to multiply numbers using scientific notation. In the accompanying classroom activity, students practice writing numbers in scientific notation and develop real-world problems for each other to solve.

In this animated Math Shorts video, see the two-dimensional figures that result from slicing solid three-dimensional figures in plane sections of cylinders and right rectangular pyramids. In the accompanying classroom activity, students create and slice clay figures and then describe the resulting shapes.

In this video, learn a strategy for solving unit rate problems. In the accompanying classroom activity, students watch the video then use grocery store ads to calculate unit rates and compare prices. They share solution strategies and consider ways that unit rates can facilitate making comparisons. To get the most from the activity, students should be comfortable finding equivalent fractions and have had some exposure to the concepts of ratio and unit rate.

In this animated ÒMath ShortsÓ video, learn about translation, which describes one way a geometric shape can move on a coordinate plane. Translation occurs when a geometric shape slides from one location to another. The shape itself doesnÕt change, just its location. The animation also explains mapping notations, which designate how far and in what direction a shape moves.

In this video, learn how photographers use dilations to print the same photograph in larger or smaller sizes. In the accompanying classroom activity, students consider how dilation is a geometric application of scale factor. After a brief refresher on scale, students watch the video. Then, they apply what they have learned by creating larger and smaller dilations of a picture, using the coordinate plane as their canvas. Students consider how both scale factor and the center of dilation influence the size and placement of the drawings they make.

In this video, learn how writing an algebraic equation can help solve a real-life scenario—in this case, determining in advance when to buy a supply of cat food. Learning how to translate a real-life scenario to mathematical language is an important skill. In the accompanying classroom activity, students practice developing expressions and equations from story problems. Special attention is paid to identifying the variable. Students also take turns as mathematicians, coming up with some of their own scenarios for their classmates to solve.