Question

拖式计算，能用简便方法计算用简便方法．17.5÷12.5×1.4 &nb...

拖式计算，能用简便方法计算用简便方法．17.5÷12.5×1.4 1.58×99+1.58 4.38÷0.125÷0.8 6，4×4.5+3.6×4.5 ?21÷0.25÷0.4 2×9.9+0.1 0.125×3.2×0.25 3.5×0.7+5.5×0.7+0.7．

Answer 1

（1）17.5÷12.5×1.4
=1.4×1.4
=1.96；

（2）1.58×99+1.58
=1.58×（99+1）
=1.58×100
=158；

（3）4.38÷0.125÷0.8
=4.38÷（0.125×0.8）
=4.38÷0.1
=43.8；

（4）6.4×4.5+3.6×4.5
=（6.4+3.6）×4.5
=10×4.5
=45；

（5）21÷0.25÷0.4 
=21÷（0.25×0.4）
=21÷0.1
=210；

（6）2×9.9+0.1
=19.8+0.1
=19.9；

（7）0.125×3.2×0.25
=0.125×8×（0.4×0.25）
=1×0.1
=0.1；

（8）3.5×0.7+5.5×0.7+0.7
=（3.5+5.5+1）×0.7
=10×0.7
=7．

Answer 2

17、5÷12.5xl、4＝l、96