1.1×1.9+1.1×7.2+0.99巧算一定要巧算

问题描述:

1.1×1.9+1.1×7.2+0.99巧算
一定要巧算

1.1×1.9+1.1×7.2+0.99
=1.1×(1.9+7.2)+0.99
=1.1×9.1+0.99
=1.1×9.1+1.1×0.9
=1.1×10
=11.