3.1×4.5+55×0.31 简算

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/29 12:57:51

3.1×4.5+55×0.31 简算
3.1×4.5+55×0.31 简算

3.1×4.5+55×0.31 简算
=3.1×4.5+5.5×3.1
=3.1×(44.5+5.5)
=3.1×10
=31

3.1×4.5+55×0.31
=3.1x4.5+5.5x3.1
=3.1x(4.5+5.5)
=3.1x10
=31

3.1×4.5+55×0.31
=3.1×4.5+5.5×3.1
=3.1×(4.5+5.5)
=31

0.31*45+0.31*55
=0.31*(45+55)
=0.31*100
=31

3.1*(4.5+5.5)=31

晕,这是上课没认真的小学生吗?
碰到这种题首先要观察,发现3.1和0.31相差十倍,则可以换成相同的
3.1x4.5+55X0.31
=3.1x4.5+5.5x3.1
=3.1x(4.5+5.5)
=3.1x10
=31