6x999+6x99x7+7+3X9+3简便方法？

Question

如题所述

Answer 1

6×999+6×99×7+7+3×9+3
=6(1000-1)+42(100-1)+10+27
=6000-6+4200-42+37
=(6000+4200)-(6+42-37)
=10200-11=10189

Answer 2

6x999+6x99x7+7+3X9+3
=9x(666+66x7)+37
=9x(666+462)+37
=9x1128+37
=(10-1)x1128+37
=11280-1128+37
=11280-1091
=10189

Answer 3

6×999+6×99×7+7+3×9+3
=6×1000-6×1+42×99+7+3×（9+1）
=6000+42×100-42×1+1+3×10
=10200-（42-31）
=10200-11
=10189