Question

能简便的用简便方法计算．5×0.46×0.2 1.25×0.4×0.8×5

能简便的用简便方法计算．5×0.46×0.2 1.25×0.4×0.8×5 1.01×7.9 59×101-4.59 8.79×99+8.79 3.4×8-1.9．

Answer 1

（1）5×0.46×0.2
=（5×0.2）×0.46
=1×0.46
=0.46；

（2）1.25×0.4×0.8×5
=（1.25×0.8）×（0.4×5）
=1×2
=2；

（3）1.01×7.9
=（1+0.01）×7.9
=7.9+0.01×7.9
=7.9+0.079
=7.979；

（4）59×101-4.59
=59×（100+1）-4.59
=59×100+59-4.59
=5900+59-4.59
=5959-4.59
=5954.41；

（5）8.79×99+8.79
=8.79×（99+1）
=8.79×100
=879；

（6）3.4×8-1.9
=27.2-1.9
=25.3．