Question

用简便方法运算

用简便方法运算，并写出运算过程
9.9*9.9+9.9*0.2+0.01＝
需要几个简略步骤，各位写一点就行啦！！多谢！！

Answer 1

9.9×（9.9+0.1）+9.9×0.1+0.01=99+0.99+0.01=100

Answer 2

9.9*9.9+9.9*0.2+0.01＝ 9.9*(9.9+0.1)+(9.9*0.1+0.01)＝ 99+1=100

Answer 3

9.9*9.9+9.9*0.2+0.01
=9.9×(9.9+0.2)+0.01
=9.9×(10+0.1)+0.01
=99+0.99+0.01
=99+1
=100

Answer 4

9.9(9.9+0.2)+0.01然后99.99+0.01=100

Answer 5

9.9*9.9+9.9*0.2+0.01＝( 10-0.1)(10-0.1)+(10-0.1)*0.2

Answer 6