EDU 2110 Manipulatives Activity 1: Operations and Algebraic Thinking K.OA.A.3 K. OA. A. 3. Kindergarten Operations & Algebraic Thinking Understand addition as putting together and adding to, and understand subtraction as taking apart and taking from. Decompose numbers less than or equal to 10 into pairs in more than one way, e.g., by using objects or drawings, and record each decomposition by a drawing or equation (e.g., 5 = 2 + 3 and 5 = 4 + 1). Material Ten frame mat (pdf blank 2-sided) Two-color counters (red/yellow - from manipulatives kit) Step Place a single ten-frame in front of you vertically. Place a pile of at least 10 two-color counters to your left. Follow the activity examples below, which mirror how you might teach the activity to your students. Make notes next to any part that seems unclear or could be difficult for some students to understand based on the grade level of the activity. Example 1 Place 6 red counters on the ten frame: How many counters in all? (answer is 7) Then place 1 yellow counter on the ten frame: You just showed 6 + 1 = 7 Example 2 Let's look at another way to make 7. (this is decomposing the number) Flip all of the left counters over to yellow: What addition problem can we write now to show 7? (answer is 4 + 3 = 7 OR 3 + 4 = 7) What other ways can we show 7? (possible answers are below) 2+5=7 5+2=7 0 + 7 = 7 OR 7 + 0 = 7 Reflection questions: How does using a ten-frame and two color counters help students understand decomposition of numbers less than or equal to 10? Why is it important for students to decompose a number? What are some ways you could expand this activity to show multiple decompositions