Ответ:

а) 5 + 18 = 23; 123 + 7 = 130; 66 + 34 = 100; 78 + 97 = 175.

б) 276 − 13 = 263; 80 − 25 = 55; 630 − 60 = 570; 123 − 34 = 89.

в) 12 · 4 = 48; 70 · 10 = 700; 25 · 4 = 100; 14 · 3 = 42.

г) 60 : 10 = 6; 210 : 7 = 30; 204 : 2 = 102; 150 : 25 = 6.