Question

用简便方法计算下面各题．
（1）2.9×0.45+0.29×4.2+0.029×13
（2）3.84×9.6+0.96×61.6．

Answer 1

（1）2.9×0.45+0.29×4.2+0.029×13，
=2.9×0.45+2.9×0.42+2.9×0.13，
=2.9×（0.45+0.42+0.13），
=2.9×1，
=2.9；

（2）3.84×9.6+0.96×61.6，
=3.84×9.6+9.6×6.16，
=（3.84+6.16）×9.6，
=10×9.6，
=96．