Demonstrates how to solve 35 - 8 using drawings of base ten cubes to show the regrouping of ones and tens. [3:11]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This short video and interactive assessment activity is designed to teach second graders an overview of subtraction (numbers up to 20).

Demonstrates how to subtract 25 from 83 using drawings of base ten cubes to show the regrouping of ones and tens. [5:27]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This short video and interactive assessment activity is designed to teach third graders about subtraction: completing the subtraction sentence.

This short video and interactive assessment activity is designed to teach fourth graders about subtraction: completing the subtraction sentence.

A video showing an example of how to solve a two-step subtraction word problem. [3:32]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This is a video and interactive assessment activity designed to help first graders learn about subtraction word problems up to twenty.

Download these worksheets to sharpen your subtraction skills. Sheets focus on single and multi-digit subtraction, subtracting across zeros and calculating complements, and subtracting in other base number systems.

Use a visual model to subtract fractions with unlike denominators. This video focuses on using an equivalent fractions chart to compare fractions and find the missing piece.

This short video and interactive assessment activity is designed to teach second graders an overview of subtraction (numbers up to 10).

This short video and interactive assessment activity is designed to teach second graders about subtracting by counting backward with pictures.

This course features a video review and an assessment practice of subtracting by crossing out with pictures for word problems. It is aimed at first grade math students.

This short video and interactive assessment activity is designed to give fourth graders an overview of addition (sums to 1,000).

This short video and interactive assessment activity is designed to teach second graders an overview of addition (sums to 1,000).

This short video and interactive assessment activity is designed to teach third graders an overview of addition (sums to 1,000).

Create your own addition/subtraction math facts worksheets. Use them in the classroom for practice or timed drills, or at home! Choose from two levels of difficulty, and vertical or horizontal equation format. You input minimum and maximum values of the numbers to be used, as well as how many questions you'd like, and the site does the rest!

On this site from Aussie School House Teachers on the Web, an Australian K-6 teacher defines and illustrates more than 500 mathematical terms. It is a wonderful dictionary featuring clear and often interactive graphics, great colors, and lots of examples. It has been recently updated adding more terms, charts, and an app.

Download these free worksheets to sharpen your math skills. These Thanksgiving math worksheets focus on topics including comparing, patterning, addition, subtraction, multiplication, and division.

This task presents an incomplete problem and asks students to choose numbers to subtract (subtrahends) so that the resulting problem requires different types of regrouping. This way students have to recognize the pattern and not just follow a memorized algorithm--in other words, they have to think about what happens in the subtraction process when we regroup. This task is appropriate to use after students have learned the standard US algorithm.

Students develop a physical understanding for the meaning of equality by trying to find equal lengths using rods.