拖式计算，能用简便方法计算用简便方法．（1）17.5÷12.5×1.4（2）6.4×4.5+3.6×4.5（3）3.6×201（4）4×0.8×12.5

Question

拖式计算，能用简便方法计算用简便方法．
（1）17.5÷12.5×1.4                         （2）6.4×4.5+3.6×4.5
（3）3.6×201                                （4）4×0.8×12.5×2.5．

Answer 1

（1）17.5÷12.5×1.4
=1.4×1.4
=1.96

（2）6.4×4.5+3.6×4.5
=（6.4+3.6）×4.5
=10×4.5
=45

（3）3.6×201
=3.6×（200+1）
=3.6×200+3.6×1
=720+3.6
=723.6

（4）4×0.8×12.5×2.5
=（4×2.5）×（0.8×12.5）
=10×10
=100