Усний рахунок 1/2·1/31/2·1/3 5:10 0,5·100 1/2+1/3 0,7· (-8) 5:100,5·1001/2+1/30,7· (-8) 1/2·1/35:100,5·1001/2+1/30,7· (-8) 1/2:1/31/2:1/3 -17+4 9-15 -100·1/4 -11· (-12) -17+4 9-15-100·1/4-11· (-12) 1/2:1/3-17+4 9-15-100·1/4-11· (-12) 30·(-0,2)30·(-0,