Question

7.89*9.99+6.33*3.33的简便计算方法？

Answer 1

拆分9.99，变成3下3.33
7.89x9.99+6.33x3.33
=7.89x3x3.33+6.33x3.33
=（7.89x3+6.33）x3.33
=30x3.33=99.9

Answer 2

7.89×9.99+6.33×3.33
=7.89×9.99+2.11×3×3.33
=7.89×9.99+2.11×9.99
=9.99×(7.89+2.11)
=9.99×10
=99.9
利用乘法分配律的逆运算即可