小数乘法的简便计算56.5x9.9+56.5
问题描述：
小数乘法的简便计算56.5x9.9+56.5
答
56.5x9.9+56.5
=56.5*(9.9+1)
=56.5*(11-0.1)
=56.5*11-56.5*0.1
=621.5-5.65
=615.85
答
56.5*(9.9 + 1)
=56.5 * (10 + 0.1) =565 + 5.65 = 570.65
答
56.5×9.9+56.5
=56.5×（10-0.1）+56.5
=565-5.65+56.5
=621.5-5.65
=615.85