一些数奥简便运算题!(见补充)要有完整的过程和答案!
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一些数奥简便运算题!(见补充)要有完整的过程和答案!
9+99+999+9999+99999
199999+19999+1999+199+9
(1+3+5+…+1989)-(2+4+6+…+1988)
389+387+383+385+384+386+388
(4942+4943+4938+4939+4941+4943)\6
54+99*99+45
9999*2222+3333*3334
1999+999*999
求(1988*9)*(1988*9)*(1988*9)的末位有多少个0
9+99+999+9999+99999
199999+19999+1999+199+9
(1+3+5+…+1989)-(2+4+6+…+1988)
389+387+383+385+384+386+388
(4942+4943+4938+4939+4941+4943)\6
54+99*99+45
9999*2222+3333*3334
1999+999*999
求(1988*9)*(1988*9)*(1988*9)的末位有多少个0
![一些数奥简便运算题!(见补充)要有完整的过程和答案!](/uploads/image/z/15524342-62-2.jpg?t=%E4%B8%80%E4%BA%9B%E6%95%B0%E5%A5%A5%E7%AE%80%E4%BE%BF%E8%BF%90%E7%AE%97%E9%A2%98%21%EF%BC%88%E8%A7%81%E8%A1%A5%E5%85%85%EF%BC%89%E8%A6%81%E6%9C%89%E5%AE%8C%E6%95%B4%E7%9A%84%E8%BF%87%E7%A8%8B%E5%92%8C%E7%AD%94%E6%A1%88%21)
1.
9+99+999+9999+99999
=10+100+1000+10000+100000-1-1-1-1-1
=111110-5
=111105
2.
199999+19999+1999+199+9
=200000+20000+2000+200+9-4
=222200+5
=222205
3.
(1+3+5+…+1989)-(2+4+6+…+1988)
=(1-2)*995
=-995
4.
389+387+383+385+384+386+388
=(389+383)*7/2
=2 702
5.
(4942+4943+4938+4939+4941+4943)\6
=(4939+4943)*6/2/6
=(4939+4943)/2
= 4 941
6.
54+99*99+45
=9*6+9*5+99*99
=9*11+99*99
=99*1+99*99
=99*100
=9900
7.
9999×2222+3333×3334
=3333*6666+3333*3334
=3333*(6666+3334)
=3333*10000
=33330000
8.
1999+999*999
=1999+(1000-1)*(1000-1)
=1000000
9.
(1988*9)*(1988*9)*(1988*9)个位是
8*9*8*9*8*9 没有0
9+99+999+9999+99999
=10+100+1000+10000+100000-1-1-1-1-1
=111110-5
=111105
2.
199999+19999+1999+199+9
=200000+20000+2000+200+9-4
=222200+5
=222205
3.
(1+3+5+…+1989)-(2+4+6+…+1988)
=(1-2)*995
=-995
4.
389+387+383+385+384+386+388
=(389+383)*7/2
=2 702
5.
(4942+4943+4938+4939+4941+4943)\6
=(4939+4943)*6/2/6
=(4939+4943)/2
= 4 941
6.
54+99*99+45
=9*6+9*5+99*99
=9*11+99*99
=99*1+99*99
=99*100
=9900
7.
9999×2222+3333×3334
=3333*6666+3333*3334
=3333*(6666+3334)
=3333*10000
=33330000
8.
1999+999*999
=1999+(1000-1)*(1000-1)
=1000000
9.
(1988*9)*(1988*9)*(1988*9)个位是
8*9*8*9*8*9 没有0