0.9+9.9+99.9+999.9+9999.9怎样用简便方法计算

2024-11-22 09:33:38
推荐回答(2个)
回答1:

0.9+9.9+99.9+999.9+9999.9
=1-0.1+10-0.1+100-0.1+1000-0.1+10000-0.1
=1+10+100+1000+10000-0.1×5
=11111-0.5
=11110.5

回答2:

0.9+9.9+99.9+999.9+9999.9
=1+10+100+1000+10000-(0.1+0.01+0.001+0.0001)
=11111-0.1111
=1 110.8889