四年级数学《简便运算》例题（各类型汇总）.docxVIP

四年级数学《简便运算》例题（各类型汇总）

第一类

(200+5)×14

=200×14+5×14

=2800+70

=2870

25×(4+8)

=25×4+25×8

=100+200

=300

32×(25+125)

=32×25+32×125

=4×25×8+8×125×4

=4800

第二类

72×101

=72×(100+1)

=72×100+72×1

=7200+72

=7272

504×25

=(500+4)×25

=500×25+25×4

=12500+100

=12600

404×25

=(400+4)×25

=400×25+25×4

=10000+100

=10100

第三类

99×75

=(100-1)×75

=100×75-75×1

=7500-75

=7425

99×18

=(100-1)×18

=18×100-18×1

=1800-18

=1782

99×36

=(100-1)×36

=100×36-36×1

=3600-36

=3564

第四类

99×15+15

=(99+1)×15

=100×15

=1500

25+199×25

=(199+1)×25

=200×25

=5000

126×25×4

=126×(25×4)

=126×100

=12600

第五类

88×125

=(80+8)×125

=80×125+8×125

=10000+1000

=11000

72×125

=9×8×125

=9×(8×125)

=9×1000

=9000

125×32×8

=125×8×32

=1000×32

=32000

第六类

5600÷25÷4

=5600÷(25×4)

=5600÷100

=56

9000÷4÷75

=9000÷(4×75)

=9000÷300

=30

3000÷125÷8

=3000÷(125×8)

=3000÷1000

=3

第七类

1200-624-76

=1200-(624+76)

=1200-700

=500

3200-726-874

=3200-(726+874)

=3200-1600

=600

283-83-17

=283-(83+17)

=283-100

=183

第八类

378+464+22+36

=(378+22)+(464+36)

=400+500

=900

632+780+368

=632+368+780

=1000+780

=1780

第九类

415-(78+15)

=415-15-78

=400-78

=322

798-(98-39)

=798-98+39

=700+39

=739

465-(65+128)

=465-65-128

=400-128

=272

第十类

589-275+75

=589-(275-75)

=589-200

=389

946-678+78

=946-(678-78)

=946-600

=346

780-199+99

=780-(199-99)

=780-100

=680

第十一类

681-299

=(680+1)-(300-1)

=680+1-300+1

=382

157-99

=(157-1)-(99+1)

=156-100

=56

358-199

=(357+1)-(200-1)

=357+1-200+1

=159

第十二类

196×101-196

=196×(101-1)

=196×100

=19600

76×102-76×2

=76×(102-2)

=76×100

=7600

18×34-34×8

=34×(18-8)

=34×10

=340