用简便方法计算 9.9+9.99+9.999+9.9999+10.1111?

2025-04-13 09:08:22
推荐回答(2个)
回答1:

9.9+9.99+9.999+9.9999+10.1111
=9.9+9.99+9.999+9.9999+10+0.1+0.01+0.001+0.0001
=(9.9+0.1)+(9.99+0.01)+(9.999+0.001)+(9.9999+0.0001)
=10+10+10+10
=40

回答2:

9.9+9.99+9.999+9.9999+10.1111
=10×4-0.1-0.01-0.001-0.0001+10.1111
=50