Tính bằng cách thuận tiện: a) 1 267 + 99 + 501 25 × 14 × 4 b) 3 905 × (50 – 1) 270 : (27 × 2)
Tính bằng cách thuận tiện:
|
a) 1 267 + 99 + 501 25 × 14 × 4 |
b) 3 905 × (50 – 1) 270 : (27 × 2) |
c) 115 × 58 + 115 × 42 136 × 67 – 136 × 66 |
a) 1 267 + 99 + 501 = 1 267 + (99 + 501) = 1 267 + 600 = 1 867
25 × 14 × 4 = (25 × 4) × 14 = 100 × 14 = 1 400
b) 3 905 × (50 – 1) = 3 905 × 50 – 3 905 = 195 250 – 3 905 = 191 345
270 : (27 × 2) = 270 : 27 : 2 = 10 : 2 = 5
c) 115 × 58 + 115 × 42 = 115 × (58 + 42) = 115 × 100 = 11 500
136 × 67 – 136 × 66 = 136 × (67 – 66) = 136 × 1 = 136