简便计算:98.4×9.8+9.84×20
问题描述:
简便计算:98.4×9.8+9.84×20
答
98.4×9.8+9.84×20
=98.4*(10-0.2)+9.84*10*2
=984-98.4*2/10+98.4*2
=984-98.4*2*(1-0.1)
=984-177.12
=806.88