【西师大版】四年级数学下册第二单元乘除法的关系和运算律2.6练习五课时练

2.6练习五1.99X37125X (100-8)103X58125X88102X8578X 12 + 89X78-78答案：99X37=(100-1) X37= 100X37-1X37=3700 —