89 − 6 = 83; 13 − 8 = 5; 62 + 10 = 72; 9 : 3 = 3; 25 + 50 = 75; 90 − 24 = 66; 86 − 4 = 82; 11 − 7 = 4; 4 · 2 = 8; 8 + 31 = 39; 3 · 6 = 18; 30 + 40 = 70; 50 + 20 = 70; 14 : 2 = 7; 16 + 3 = 19; 97 − 35 = 62; 3 · 4 = 12; 42 + 39 = 81; 59 − 28 = 31; 23 − 3 = 20.