1999*3.14+199.9*31.4+19.99*314 简算
问题描述：
1999*3.14+199.9*31.4+19.99*314 简算
答
1999*3.14+199.9*31.4+19.99*314
=1999×3.14+1999×3.14+1999×3.14
=1999×3.14×3
=（2000-1）×9.42
=18840-9.42
=18830.58