五年级上册数学 【小数乘法简便运算】三大拔高题型

五年级上册数学 【小数乘法简便运算】三大拔高题型


简介:
类型(一):“拆分型”——“99”、“101”、“补1”型 (1)8.75×11-8.75 (2)0.67×99 =8.75×11-8.75×1 =0.67×(100-1) =8.75×(11-1) =0.67×100-0.67×1 =8.75×10 =67-0.67 =87.5 =66.33 (3)8.8×1.25 (4)79×2.5+22×2.5-2.5 =1.1×8×1.25 =79×2.5+22×2.5-2.5×1 =1.1×(8×1.25) =(79+22-1)×2.5 =1.1×10 =100×2.5 =11 =250