SIX SUBTRACTION STRATEGIES

#1 Round the Subtrahend to a Multiple of 10 and Adjust: 63 – 28 = 63 – 30 = 33 33 + 2 = 35

#1 Round the Subtrahend to a Multiple of 10 and Adjust: 81 – 47 =

#2 Decompose the Subtrahend 63 - 28 63 – 20 = 43 43 – 3 = 40 40 – 5 = 35

#2 Decompose the Subtrahend Another Way 63 - 28 63 – 3 = 60 60 – 20 = 40 40 – 5 = 35

#2 Decompose the Subtrahend 81 – 49 =

#3 Add Instead 63 - 28 28 + 30 = 58 58 + 2 = 60 60 + 3 = 30 30 + 2 + 3 = 35

30 + 2 + 3 = 35 + 30 + 2 + 3 58 60 63 28

#3 Add Instead 2nd Way 63 - 28 28 + 2 = 30 30 + 30 = 60 60 + 3 = 30 2 + 30 + 3 = 35

2 + 30 + 3 = 35 + 2 + 30 + 3 30 60 63 28

#3 Add Instead 95 - 46

#4 Same Difference 63 - 28 + 2 + 2 65 - 30 30 65 + 2 + 2 28 63

#4 Same Difference 63 - 28 + 2 + 2 65 - 30 35 30 65 + 2 + 2 28 63

#4 Same Difference 100 - 37 - 1 - 1 99 - 36 63 36 99 - 1 - 1 37 100

- 63 – 28 40 – 5 = 35 #5 Break Apart by Place (Start on the Left) 6 3 2 8 40 - 5 40 – 5 = 35

#5 Break Apart by Place (Start on the Left) 93 - 27

#5 Break Apart by Place (Start on the Left) 524 - 189

- 63 - 28 35 #6 Standard Algorithm Change 63 into 5 tens or 50 and 13 ones 5 13 35 - 6 3 2 8

#6 Standard Algorithm 17 - 9 17 8 17 - 9