简便计算1.99乘9.9加0.099
问题描述：
简便计算1.99乘9.9加0.099
答
=1.99×9.9+9.9×0.01
=(1.99+0.01)×9.9
=2×9.9
=1.98
答
原式=1.99×9.9+0.01×9.9
=9.9×(1.99+0.01)
=9.9×2
=19.8
答
1.99*9.9+0.099
=1.99*9.9+0.01*9.9
=(1.99+0.01)*9.9
=2*9.9
=19.8