文档介绍:该【小学生奥数加减法的巧算练习题 】是由【guwutang】上传分享,文档一共【5】页,该文档可以免费在线阅读,需要了解更多关于【小学生奥数加减法的巧算练习题 】的内容,可以使用淘豆网的站内搜索功能,选择自己适合的文档,以下文字是截取该文章内的部分文字,如需要获得完整电子版,请下载此文档到您的设备,方便您编辑和打印。小学生奥数加减法的巧算练习题
(1)238+1759-97-998
=238+1759-100+3-1000+2
=238+2-100+(1759+3-1000)
=140+762
(1)998+3+99+998+3+9
=(998+2)+(1+99)+(998+2)+(1+9)
=1000+100+1000+10
=2110
(2)19+199+1999+19999+199999
=20-1+200-1+2000-1+20000-1+200000-1
=20+200+2000+20000+200000-1-1-1-1-1
=222220-5
=222215
(1)37+56+63+44
=37+63+(56+44)
=100+100
=200
(2)516-56-44-16
=516-16-56-44
=516-16-(56+44)
=500-100
=400
(3)947+(372-447)
=947+372-44
=947-447+372
=500+372
=872
(4)5498-1928-387-1072-16137
=5498-1928-1072-387-1613
=5498-(1928+1072)-(387+1613)
=5498-3000-2000
=2498-2000
=498
1、计算:123+234+345-456+567-678+789-890
123+234+345-456+567-678+789-890
=123+234+345+(567-456)+(7*78)-890
=123+234+345+111+111-890
=234+(123+567)-890
=234+690-890
=34+890-890
=34
2、569+384+147-328-167-529
569+384+147-328-167-529
=(569-529)+147-(147+20)+388-4-328
=40-20+56
=76
3、计算:6472-(4476-2480)+5319-(3323-1327)+9354-(7358-5362)+6839-(4843-2847)
6472-(4476-2480)+5319-(3323-1327)+9354-(7358-5362)+6839-(4843-2847)
=(6480-8)+(5320-1)+(9360-6)+(6840-1)-(4476-2476-4)-(3323-1323-4)-(7358-5358-4)-(4843-2843-4)
=(6480+5320)+(9360+6840)-8-1-6-1-2000+4-2000+4-2000+4-2000+4
=11800+16200-8000-16+16
=28000-8000
=20000
++=+____+
(+)+=____+(____+____)--=____〇(____〇____)
++
--
-+++
++--
67+++++
++++
++++-
++
--
-+++
++--
82+++++
++++
++++-
①36+87+64
②99+136+101
③1361+972+639+28
解:
①式=(36+64)+87
=100+87=187
②式=(99+101)+136
=200+136=336
③式=(1361+639)+(972+28)
=2000+1000=3000
①188+873
②548+996
③9898+203
解:
①式=(188+12)+(873-12)(熟练之后,此步可略)
=200+861=1061
②式=(548-4)+(996+4)
=544+1000=1544
③式=(9898+102)+(203-102)
=10000+101=10101
①300-73-27
②1000-90-80-20-10
解:
①式=300-(73+27)
=300-100=200
②式=1000-(90+80+20+10)
=1000-200=800
小学生奥数加减法的巧算练习题