用简便方法计算:5.78+19.9×57.8
问题描述：
用简便方法计算:5.78+19.9×57.8
超级急的
答
5.78+19.9×57.8
=57.8×0.1+19.9×57.8
=57.8×(0.1+19.9)
=57.8×20
=1156