Question

帮我回答一下题目（简便方法计算） 33333×6×11111+222222 1/2+1/6+1/12+1/30+1/42

Answer 1

33333×6×11111+222222

=33333*3*2*11111+200000+22222

=22222*（99999+1）+200000

=2222200000+200000

=2222400000

1/2+1/6+1/12+1/20+1/30+1/42+1/56 原式缺了+1/20

=1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8

=1-1/8

=7/8

999×888+888×777+777×666+666×555

=9*111*8*111+8*111*7*111+7*111*6*111+6*111*5*111

=（9*8+8*7+7*6+6*5）*111*111

=200*111*111

=2464200