7.8×0点99+9点九的简便计算

7.8×0点99+9点九的简便计算
2025-03-14 00:58:22
推荐回答(3个)
回答1:

7.8×0点99+9点九
=7.8×0.99+0.99×10
=0.99×(7.8+10)
=(1-0.01)×17.8
=17.8-0.178
=17.622。

回答2:

7.8×0.99+9.9
=9.9×(0.78+1)
=9.9×1.78
=(10-0.1)×1.78
=17.8-0.178
=17.622

回答3:

=9.9X(0.78十1)=9.9X1.78=10X1.78一0.1X1.78=17·8一0.178=17.622