вычисли удобным способом. 48+7+3 37+9+3 12+8+26+4 37+13+7+3. 64+18+6+12 71+16+4+9

Решение:

1) 48 + 7 + 3 = 48 + (7 + 3) = 48 + 10 = 58

2) 37 + 9 + 3 = (37 + 3) + 9 = 40 + 9 = 49

3) 12 + 8 + 26 + 4 = (12 + 8) + (26 + 4) = 20 + 30 = 50

4) 37 + 13 + 7 + 3 = (37 + 3) + (13 + 7) = 40 + 20 = 60

5) 64 + 18 + 6 + 12 = (64 + 6) + (18 + 12) = 70 + 30 = 100

6) 71 + 16 + 4 + 9 = (71 + 9) + (16 + 4) = 80 + 20 = 100