Question

简便运算 1.25×6.4 0.25×3.2

Answer 1

1.25x6.4
=1.25x8x0.8
=10x0.8
=8

追答

0.25x3.2
=0.25x4x0.8
=1x0.8
=0.8

追问

简便运算
2.9×0.45+0.29×4.2+0.029×13
3.84×9.6+0.96×61.6

追答

2.9x0.45+0.29x4.2+0.029x13
=2.9x0.45+2.9x0.42+2.9x0.13
=2.9x（0.45+0.42+0.13）
=2.9x1
=2.9

3.84x9.6+0.96x61.6
=3.84x9.6+9.6x6.16
=9.6x（3.84+6.16）
=9.6x10
=96