求2道计算题,谢谢!一:9+99+999+9999 二:998+997+996+1002+1003+1004 = = = =
求2道计算题,谢谢!一:9+99+999+9999 二:998+997+996+1002+1003+1004 = = = =
9+99+999+9999
=1+9+1+99+1+999+1+9999-4
=11110-4
=11106
二:
998+997+996+1002+1003+1004
=(998+1002)+(997+1003)+(996+1004)
=2000+2000+2000
=6000
998+997+996+1002+1003+1004的简便方法计算
998+997+996+1002+1003+1004
=(998+1002)+(997+1003)+(996+1004)
=2000+2000+2000
=6000
999+998+997十996+1000+1004+1003+1002+1001
999+998+997+996+1000+1004+1003+1002+1001
=(999+1001)+(998+1002)+(997+1003)+(996+1004)+1000,
=2000×4+1000,
=9000.
计算拍伍:(1)454十999×999十545(2)999十998十997十996十1000十1004十1003十1002十运贺则1001(3)125×198÷
(1)454+999×999+545
=454+999×(1000-1)+545,
=454+999×1000-999+545,
=454+545-999+999000,
=999-999+999000,
=999000;
(2)999+998+997+996+1000+1004+1003+1002+1001.
=(999+1001)+(998+1002)+(997+1003)+(996+1004)+1000,
=2000+2000+2000+2000+1000,
=9000;
(3)125×198÷﹙18÷8),
=125×198÷18×8,
=(125×8)×(198÷18),
=1000×11,
=11000;
(4)2772÷28+34965÷35
=(2800-28)÷28+(35000-35)÷35,
=100-1+1000-1,
=99+999,
=1098;
(5)1+2+3+4…+99+100,
=(1+100)+(2+99)+…+(50+51),
=101×50,
=5050.
1002+1003+1004+998+997+996
(1002+998)+(1003+997)+(1004+996)=6000
用简便方法计算:998+1005+1001+997+1000+1002+999+998+1004+996
用凑整法:
998+1005+1001+997+1000+1002+999+998+1004+996
=(996+1004)+(998+1002)+(999+1001)+(998+997+1005)+1000
=2000+2000+2000+3000+1000
=10000
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以后有问题也能问我.
999+998+997+1000+1004+1003+1002+1001=?
=(999+1001)+(998+1002)+(997+1003)+1000+1004
=2000+2000+2000+1000+1004
=8004
996+997+998+999+1000+1001+1002+1003如何简便计算。
996+997+998+999+1000+1001+1002+1003
=996+(997+1003)+(998+1002)+(999+1001)+1000
=996+2000+2000+2000+1000
=7996
998 997 996 1002 1003 1004怎样脱式
998+997+996+1002+1003+1004脱式
=(998+1002)+(997+1003)+(996+1004)
=2000+2000+2000
=6000。