Question

6.49×4.3 67.9×0.57的简便运算

Answer 1

6.49x4.3+67.9x0.57
=6.49x4.3+6.49x5.7+0.3x5.7
=64.9+1.71
=66.61

Answer 2

因为6.49×4.3=64.9×0.43，所以原式等于64.9×0.43+67.9×0.57，运用乘法分配律逆运算可以有64.9×（0.43+0.57）=64.9