小学六年级数学计算题三则

1.
33333*6*11111+22222
=(199998+2)*11111
=200000*11111
=2222200000
2.
1/2 +1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8
=7/8
3.
999 * 888 +888 * 777 + 777 * 666 + 666 * 555
=111*111*(9*8+8*7+7*6+6*5)
=111*111*(16*8+12*6)
=111*111*200
=12321*200
=2464200

用计算机算

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

1. 33333*6*11111+22222
=33333*3*2*11111+22222
=99999*22222+22222
=(99999+1)*22222
=100000*22222
=2222200000

1.33333*6*11111+22222
=11111*3*6*11111+22222
=11111*3*2*3*11111+22222
=22222*99999+22222
=22222（99999+1）
=22222000000
2.1/2+1/6+1/20+1/30+1/42+1/56
=1/2+1/2*1/3+1/4*1/5+1/5*1/6+1/6*1/7+1/7*1/8
=1/2（1+1/3）+1/5（1/4+1/6）+1/7(1/6+1/8)
=1/2*4/3+1/5*5/12+1/7*7/24
=2/3+1/