5.6×0.375+38×5.4-0.375×0.9.

问题描述:

5.6×0.375+

3
8
×5.4-0.375×0.9.

5.6×0.375+

3
8
×5.4-0.375×0.9,
=5.6×0.375+0.375×5.4-0.375×0.9,
=(5.6+5.4-0.9)×0.375,
=10.1×0.375,
=(10+0.1)×0.375,
=10×0.375+0.1×0.375,
=3.75+0.0375,
=3.7875.
答案解析:把分数化为小数,运用乘法分配律的逆运算简算,计算后得10.1×0.375,然后把10.1看做10+0.1,运用乘法分配律简算.
考试点:小数的巧算.
知识点:对于巧算的题目,法则、定律或性质是进行计算的依据,掌握运算技巧是解答的关键.