In this Subtraction as an Unknown Addend Activity, students find the unknown whole number in addition and subtraction equations up to 20.

In this Adding Two Digit Numbers Activity, students add up to four two-digit numbers using strategies based on place value and properties of operations.

In this Adding and Subtracting Unknown Numbers Activity, students find the unknown whole number in addition and subtraction equations up to 20.

Using Subtraction With 2-3-4-5 Differences Activity , students subtract single digit subtraction equations, then sort differences into categories.

Using Subtraction With 6-7-8-9 Differences Activity, students solve single digit subtraction equations, then sort answers into categories.