Understanding the inverse relationship between addition and subtraction is essential for developing fluency in young mathematicians. Zoe and RJ explain how three numbers can form fact families that make two addition and two subtraction...

Second graders practice their problem solving skills. In this addition and subtraction skills lesson, 2nd graders solve word problems that require them to find differences and sums. This lesson features the use of a video titled...

Third graders explore their addition and subtraction skills. In this number sense instructional activity, 3rd graders analyze different scoring possibilities for a basketball game. This instructional activity incorporates the...