101*8.7+4.9怎样简算？

100*8.7+1+4.9

101*8.7+4.9
=（100+1）*8.7+4.9
=100*8.7+1*8.7+4.9
=870+8.7+4.9
=878.7+4.9
=883.6

一个两位数（比如说是ab）乘以101，等于abab;
所以101*8.7=878.7
再心算加5-0.1即可。
如何？
我可是北京八中少儿班毕业的！

对对对

101分解成100＋1

101*8.7+4.9
=(100+1)*8.7+4.9
=100*8.7+1*8.7+4.9
=870+8.7+4.9
=883.6