17 + 73 = 90; 77 : 7 = 11; 56 − 25 = 31; 68 : 4 = 17; 60 − 15 = 45; 13 + 64 = 77; 12 : 12 = 1; 97 − 71 = 26; 80 : 5 = 16; 54 − 4 = 50; 18 + 50 = 68; 16 : 8 = 2; 8 + 27 = 35; 36 − 22 = 14; 24 : 8 = 3; 22 + 39 = 61; 72 : 18 = 4; 400 : 8 = 50; 75 + 47 = 122; 95 − 88 = 7.