Question

0.645+10.9x6.5的递等式简便计算。

Answer 1

0.645+10.9x6.5的递等式简便计算。
解：
采用分配律，
原式=0.645+10.9x6.5
=0.645+（10+0.9）x6.5
=0.645+10x6.5+0.9x6.5
=0.645+65+5.85
=65.645+5.85
=71.495

Answer 2

0.645+10.9x6.5
=0.645+10x6.5+0.9×6.5
=0.645+65+1×6.5-0.1×6.5
=0.645+71.5-0.65
=71.5-0.005
=71.495