28 − 7 =; 27 + 60 =; 61 − 23 =; 33 + 33 =; 48 − 1 =; 27 + 42 =; 96 − 32 =; 55 + 18 =; 90 − 52 =; 12 + 51 =; 71 − 51 =; 18 + 6 =; 86 − 64 =; 8 + 67 =; 23 − 11 =; 58 + 7 =; 72 − 50 =

28 − 7 = 21; 27 + 60 = 87; 61 − 23 = 38; 33 + 33 = 66; 48 − 1 = 47; 27 + 42 = 69; 96 − 32 = 64; 55 + 18 = 73; 90 − 52 = 38; 12 + 51 = 63; 71 − 51 = 20; 18 + 6 = 24; 86 − 64 = 22; 8 + 67 = 75; 23 − 11 = 12; 58 + 7 = 65; 72 − 50 = 22.