This short video and interactive assessment activity is designed to teach fifth graders about adding and subtracting.

This short video and interactive assessment activity is designed to teach fourth graders about adding and subtracting.

Kahn Academy video - How to add and subtract fractions with like and unlike denominators.

This short video and interactive assessment activity is designed to teach fourth graders about adding and subtracting money with pictures in columns.

This is an interactive assessment and video designed to teach Adding and Subtracting (Numbers up to 20) - Word Problems to first graders.

This short video and interactive assessment activity is designed to teach fourth graders about adding and subtracting terms (numbers to 100).

This short video and interactive assessment activity is designed to teach fifth graders about adding and subtracting with parentheses.

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

The purpose of this task is to study some patterns in a small addition table. Each pattern identified persists for a larger table and if more time is available for this activity students should be encouraged to explore these patterns in larger tables.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important aspects of the task and its potential use.

Students place markers on the numbers 2-12. Students toss two 6-sided dice, find the sum and remove a marker from that number, if there is still one. The first player to remove all markers wins the game. This game can be used as addition practice or as an introduction to the probability of the different outcomes of rolling two dice. This game was developed by a Monmouth University student for the Probability Fair. These games help students acquire proficiency in addition and subtraction facts.

This short video and interactive assessment activity is designed to teach fourth graders about one step metric capacity with addition and subtraction - word problems.

This short video and interactive assessment activity is designed to teach third graders about one step addition and subtraction - word problems.

This short video and interactive assessment activity is designed to teach fifth graders about addition in kilograms.

This short video and interactive assessment activity is designed to teach fourth graders about addition of capacities - word problems.

This short video and interactive assessment activity is designed to teach fifth graders about addition of compound unit capacities - word problems.

This short video and interactive assessment activity is designed to teach third graders about addition of sequential capacities - word problems.

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

This short video and interactive assessment activity is designed to teach second graders an overview of addition.

An interactive applet and associated web page that show the concept of adjacent angles (two angles that share a common leg). The applet shows three line segments with a common endpoint. The user can move the center one and see that the angles on both sides (the adjacent angles) of it are affected. Applet can be enlarged to full screen size for use with a classroom projector. After use in the classroom, students can access it again from any web browser at home or in the library with no login required. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.