2.9×0.45+0.29×4.2+0.029×13+怎样用简便方法计算?

问题描述:

2.9×0.45+0.29×4.2+0.029×13+怎样用简便方法计算?
0.029×0.45+0.29×4.2+0.029×13 =0.029×45+0.029×42+0.029×13 =0.029×(45+42+13) =0.029×100 =2.9

倍数拆出来%D%A我的答案怎么样?