二点8+28乘零点九的简便算法

2024-11-01 13:24:50
推荐回答(2个)
回答1:

2.8+28×0.9
=28×0.1+28×0.9
=28×(0.1+0.9)
=28

回答2:

2.8+28x0.9
=2.8+2.8x9
=2.8x(1+9)
=2.8x10
=28