This lesson contains a video lesson [9:28] and various exercises about the area of rectangles, common units of area, two-part rectangles and the distributive property, and shapes composed of rectangular areas.

This lesson presents the idea that the area of any triangle is exactly half of a certain parallelogram -- thus we get the familiar formula of multiplying the base and the altitude and taking half of that. The lesson contains varied exercises for students.

This is a complete lesson with video instruction [5:49] and varied exercises about comparing decimals with 1 or 2 decimal digits.

Video lesson [8:41] explains various methods for comparing fractions. It includes word problems and a puzzle for practice.

Lesson shows the concept of a mixed number with the help of visual models and number lines.

This is a complete lesson with a video [7:56], instruction, and exercises about dividing decimals by decimals.

This lesson studies reciprocal numbers and how to use them in fraction divisions.

This lesson teaches how to add like fractions and mixed numbers with like fractional parts using visual models (pies, fraction bars). It includes lots of exercises.

This fifth-grade lesson teaches how to add and subtract unlike fractions using a video presentation and visual models. [7:19] Includes practice exercises.

This lesson contrasts area and perimeter and has varied exercises for students about both concepts.

This lesson presents the idea that the area of any right triangle is exactly half of a certain rectangle, and contains varied exercises for students.

This review lesson about basic shapes (polygons)contains varied hands-on exercises and tilings about triangles, quadrilaterals, pentagons, and hexagons.

Complete lesson with instruction and exercises, teaching students how to divide decimals using mental math.

In this lesson, fraction divisions are solved by thinking how many times the divisor "fits" or "goes into" the dividend. Includes video, visual models, and word problems. [10:32]

In this lesson, learn how to divide fractions using the shortcut of reciprocal numbers which is shown in the accompanying video. [10:31] The lesson also includes practice problems and many word problems.

This video lesson teaches how to divide fractions by whole numbers (sharing divisions) using mental math.

Lesson teaches the concept of equivalent fractions. Accompanying video shows how to get an equivalent fraction by splitting the existing pieces further into a certain number of new pieces.

This fifth-grade lesson explores the area of a rectangle with fractional side lengths. We tile the rectangle with unit rectangles and show that the area is the same as would be found by multiplying the side lengths. We multiply fractional side lengths to find areas of rectangles.

Learn the basics of how to calculate percentages of quantities in this easy lesson. [5:22]