1.102 Вычислите: а) 27+3; 68+2; 7+2; 55+5; 34+26; б) 52−7; 36−9; 40−6; 23−8; 61−4; в) 9·8; 8·9; 9·9; 6·8; 7·0; г) 53·10; 60:10; 80:10; 1000:1000; 100:100.

а) \(27+3=30\); \(68+2=70\); \(7+2=9\); \(55+5=60\); \(34+26=60\).

б) \(52-7=45\); \(36-9=27\); \(40-6=34\); \(23-8=15\); \(61-4=57\).

в) \(9\cdot8=72\); \(8\cdot9=72\); \(9\cdot9=81\); \(6\cdot8=48\); \(7\cdot0=0\).

г) \(53\cdot10=530\); \(60:10=6\); \(80:10=8\); \(1000:1000=1\); \(100:100=1\).