四年级数学《简便运算》例题（各类型汇总）.pdf

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