In this exercise, students practice repeated addition. Students receive immediate feedback and have the opportunity to get hints, watch a tutorial video, and try questions repeatedly.

By now, students have learned that fact families include both addition and subtraction facts. They have also learned that by reversing the order of the addends, they can form related addition facts with the same sum. The students will...

An advanced investigation of Greatest Common Factors (Divisors) and a look at related algorithms and properties) comutative, associative, and more). Contains links to relevant topics.

Sixth graders are presented with a completed multiplication equation and are asked to use it to find the answers to seven other equations. To do this, they must use their reasoning and estimation skills. Aligns with 6.NS.B.3.

This site introduces the iteration of circle inversions and describes the associated properties.

This site introduces the iteration of circle inversions and describes the associated properties.

[Free Registration/Login may be required to access all resource tools.] A collection of resources that teach students that, unlike multiplication of numbers, matrix multiplication for square matrices is not a commutative operation, but...

The purpose of this task is to explore reflections in the context of paper folding. Each fold is associated with a line of reflection and understanding each step in the construction requires careful analysis of angles and of the...

This site introduces the iteration of circle inversions and describes the associated properties.

In this lesson on addition and subtraction within 20, 1st graders learn how to solve addition and subtraction story problems by finding clue words. Adding three addends is also taught in this lesson.

The basic identities and properties of addition and multiplication are listed. No explanation, simply the identities.

The Chinese character mark formerly known as "Tan" is the first of two lessons to introduce first grade students to geometry using tangrams. This lesson incorporates history, math, and language arts. In this lesson students will be able...