9.8乘9.9+0.98

问题描述:

9.8乘9.9+0.98

9.8×9.9+0.98
=9.8×(10-0.1)+0.98
=9.8×10-9.8×0.1+0.98
=98-0.98+0.98
=97.2+0.98
=98