Category 2 Adding multiples of tens while keeping on number whole and then breaking apart the ones into friendly combinations. Example: 28 + 24 could be “chunked” as 28 + 20 = 48; the 4 could be broken into 2 + 2 so that 48 + 2 = 50; 50 + 2 = 52
18 + 10 18 + 13 18 + 20 18 + 23
16 + 20 16 + 25 16 + 30 16 + 36
17 + 10 17 + 14 17 + 30 17 + 35
29 + 10 29 + 15 29 + 20 29 + 24
38 + 20 38 + 26 38 + 30 38 + 33
45 + 30 45 + 38 45 + 40 45 + 46
57 + 10 57 + 14 57 + 30 57 + 36
65 + 30 65 + 36 65 + 50 65 + 57
73 + 30 73 + 38 73 + 50 73 + 58
Category 3 Adding multiples of tens and one hundred while keeping one number whole.