Question

（1）2.89×4.37+28.9×0.451+0.289×11.2
（2）0.25×1.25×0.32．

Answer 1

分析：（1）先根据积不变规律，把算式变成2.89×4.37+2.89×4.51+2.89×1.12，然后运用乘法分配律简算；
（2）先把0.32分解成0.4×0.8再根据乘法交换律和结合律简算．

解答：解：（1）2.89×4.37+28.9×0.451+0.289×11.2
=2.89×4.37+2.89×4.51+2.89×1.12
=2.89×（4.37+4.51+1.12）
=2.89×10
=28.9；

（2）0.25×1.25×0.32
=0.25×1.25×（0.4×0.8）
=（0.25×0.4）×（0.8×1.25）
=0.1×1
=0.1．

点评：此题是考查四则混合运算，要仔细观察算式的特点，灵活运用一些定律进行简便计算．