Question

4．脱式计算，能简算的要简算：
9.8×56+0.2×56                   
64.68÷2.8+3.2
0.27×99+0.27                       
3.2×1.8+2.54．

Answer 1

分析 ①用乘法分配律计算．
②先算除法再算加法．
③用乘法分配律计算．
④先算乘法再算加法．

解答 解：①9.8×56+0.2×56
=（9.8+0.2）×56
=10×56
=560

②64.68÷2.8+3.2
=23.1+3.2
=26.3

③0.27×99+0.27
=0.27×（99+1）
=0.27×100
=27

④3.2×1.8+2.54
=5.76+2.54
=8.3

点评 考查了混合运算的运算顺序和简便方法的灵活运用．