Friendly Numbers
Incremental
Modeling
Your Choice!
100
Solve 28 + 32 using friendly numbers.
28 + 2 = 30 32 - 2 = 30 30 + 30 = 60
100
Solve 18 + 23 using incremental addition.
10 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 10 + 10 + 1 + 1 + 1 = 41
100
Use a model to solve 27 + 34.
2 rods, 7 cubes; 3 rods, 4 cubes = 61
100
75 + 22
87
200
Solve 17 + 25 using friendly numbers.
17 + 3 = 20 25 - 3 = 22 20 + 22 = 42
200
Solve 27 + 16 using incremental addition.
10 + 10 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 10 + 1 + 1 + 1 + 1 + 1 + 1 = 43
200
Use modeling to solve 34 + 23.
3 rods, 4 cubes; 2 rods, 3 cubes = 57
200
68 + 34
102
300
Solve 45 + 66 using friendly numbers.
66 + 4 = 70 45 - 4 = 41 70 + 41 = 111
300
Solve 26 + 15 using incremental addition.
10 + 10 + 1 + 1 + 1 + 1 + 1 + 1 + 10 + 1 + 1 + 1 + 1 + 1 = 41
300
Use modeling to solve 47 + 22.
4 rods, 7 cubes; 2 rods, 2 cubes = 69
300
34 + 16
40
400
Use friendly numbers to solve 45 + 37.
37 + 3 = 40 45 - 3 = 42 40 + 42 = 82
400
Solve 43 + 24 using incremental addition.
10 + 10 + 10 + 10 + 1 + 1 + 1 + 10 + 10 + 1 + 1 + 1 + 1 = 67
400
Use modeling to solve 35 + 37.
3 rods, 5 cubes; 3 rods, 7 cubes = 72
400
54 + 27
81
500
Solve 28 + 34 using friendly numbers.
28 + 2 = 30 34 - 2 = 32 30 + 32 = 62
500
Use incremental addition to solve 34 + 54.
10 + 10 + 10 + 1 + 1 + 1 + 1 + 10 + 10 + 10 + 10 + 10 + 1 + 1 + 1 + 1 = 88
500
Use modeling to solve 36 + 17.
3 rods, 6 cubes; 1 rod, 7 cubes = 53
500
76 + 12
88
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