5.6×0.375+[3/8]×5.4-0.375×0.9.

3个回答

  • 解题思路: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.

    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.

    点评:

    本题考点: 小数的巧算.

    考点点评: 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.