28 : 7 * 5;
36 : 4 * 5;
21 : 3 * 5;
8 * (25 : 5);
(6 : 2) * 5;
30 : (2 * 3);
8 * (90 − 86);
(18 + 14) : 8;
6 * (50 − 47);
90 − 46;
96 − 40;
90 − 6.
28 : 7 * 5 = 4 * 5 = 20;
36 : 4 * 5 = 9 * 5 = 45;
21 : 3 * 5 = 7 * 5 = 35;
8 * (25 : 5) = 8 * 5 = 40;
(6 : 2) * 5 = 3 * 5 = 15;
30 : (2 * 3) = 30 : 6 = 5;
8 * (90 − 86) = 8 * 4 = 32;
(18 + 14) : 8 = 32 : 8 = 4;
6 * (50 − 47) = 6 * 3 = 18;
90 − 46 = 44;
96 − 40 = 56;
90 − 6 = 84.