Fact Families: Addition and Subtraction

Facts Families: Addition and Subtraction teaches the Commutative Property of Addition. Students watch the 2 minute instructional animation and then are able to practice. This is a great app for a group setting too. Worksheet is also available online for free at www.appagogy.com. Students will learn to: • Break out fact families in addition and subtraction among three numbers from 1-20 Grade Level(s) 1 2 3 Common Core Standards 1.OA.3 Apply properties of operations as strategies to add and subtract.3 Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.) 1.OA.4 Understand subtraction as an unknown-addend problem. For example, subtract 10 - 8 by finding the number that makes 10 when added to 8. 1.OA.8 Determine the unknown whole number in an addition or subtraction equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = * - 3, 6 + 6 = *. 2.OA.2 Fluently add and subtract within 20 using mental strategies.2 By end of Grade 2, know from memory all sums of two one-digit numbers.