小学奥数思维突破经典例题《简便运算》课件——3-6年级通用

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小学奥数思维突破经典例题《简便运算》课件——3-6年级通用

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(共47张PPT)
简便运算
小学数学思维
简便运算
154+288+46
285+147+253
=
=
=
=
=
=
285+
(147+253)
285+
400
685
(154+46)
+288
200
+288
488
简便运算
99+178+122
456+588+412
=
=
=
=
=
=
456+
(588+412)
456+
1000
1456
99+
(178+122)
300
399
99+
77+56+23
简便运算
165+477+135
=
=
=
=
=
=
(77+23)
+56
100
+56
156
(165+135)
+477
+477
300
777
568-(68+178)
561-(119-39)
简便运算
=
=
=
=
=
=
568
500
322
561
561
600
481
=
-178
-68
-119
+39
-178
-119
+39
-119
382+165+35-82
534-257-34-143
简便运算
=
=
=
=
=
=
382-82+
300
+200
(165+35 )
500
534-34
534-34
-(257+143)
500
-400
100
=
-257-143
2000-368-132
简便运算
=
=
=
=
=
=
89
×(99+1)
89
×100
8900
2000-
2000-
500
1500
(368+132)
89×99+89
36+64-36+64
487-287-139-61
简便运算
=
=
=
=
=
=
36-36
+64×2
0+128
128
487-287
-(139+61)
200
-200
0
1022-478-422
672-36+64
简便运算
=
=
=
=
=
1022-
(478+422)
1022-
900
122
636+64
700
=
672-
(36+64 )
=
672-
100
=572
×
101×56
99×26
简便运算
=
=
=
=
=
=
(100+1)×56
100×56
+56
5600
+56
5656
=
(100-1)
×26
100×26
-26
2600-26
=
2574
35×8+35×6-4×35
125×32
简便运算
=
=
=
=
=
=
125×8×4
1000×4
4000
35×
(8+6-4)
35×
10
350
382×101-382
4×60×50×8
简便运算
=
=
=
=
=
=
382
×(101-1)
382
×100
38200
4×60×
2400×400
960000
(50×8)
987-(287+135)
478-256-144
简便运算
=
=
=
=
=
=
478
478
-400
78
987
900-135
765
-(256+144)
-287
-135
25×48
(40+8)×25
简便运算
=
=
=
=
=
=
25×
100
×12
1200
48
×25
12×
(4×25)
1200
4×12
97×8×125
645-180-245
简便运算
=
=
=
=
=
=
97×
97×1000
97000
645-245-180
-180
400
220
(8×125)
102×99
24×125
简便运算
=
=
=
=
=
=
3×8
3×1000
3000
102×
102×100
-102
10200
-102
1098
=
(100-1)
×125
99×56+56
3200÷4÷25
简便运算
=
=
=
=
=
=
56
×(99+1)
3200÷
56×100
5600
3200
÷100
32
(4×25)
64×15-5×64
25×(12×40)
简便运算
=
=
=
=
=
=
64×
64×
10
640
25×40×12
1000×
12
12000
(15-5)
2182-1655-345
298×99+298
简便运算
=
=
=
=
=
=
2182-
2182-2000
182
298×(99+1)
298×100
29800
(1655+345)
99×38+38
17×23-23×7
简便运算
=
=
=
=
=
=
38×(99+1)
38
×100
3800
23×(17-7)
23
×10
230
250×13×4
88×125
简便运算
=
=
=
=
=
=
250×4×13
1000×13
13000
11×(8×125)
11×1000
11000
38×99+38
简便运算
=
=
=
=
=
=
36×88+36×15-108
36×
36×88+36×15
36×100
=3600
38×(99+1)
38×100
3800
-36×3
(88+15-3)
175×56+25×56
简便运算
=
=
=
=
=
=
645-180-245
645-245-180
400-180
220
56×(175+25)
56×200
11200
3500÷14÷5
简便运算
3700÷4÷25
=
=
=
=
=
=
3500÷
3500
50
3700÷
3700÷100
37
(14×5)
(4×25)
÷70
88×1250
98×83+166
简便运算
=
=
=
=
=
=
11×8
11×
11×10000
98×83+83×2
83×(98+2)
83×100
= 8300
×1250
(8×1250)
=110000
135×27+135×72+135
789-136-64
简便运算
=
=
=
=
=
=
789-
135×(27+72+1)
135×100
13500
789-200
589
(136+64)
125×47×8
50×25×20×40
简便运算
=
=
=
=
=
=
125×8 ×47
1000
47000
(50×20)
1000×1000
1000000
×47
×(25×40)
5600÷25÷56
3900 ÷(39×4)
简便运算
=
=
=
=
=
=
5600÷56÷25
100÷25
4
3900
100÷4
25
÷39
÷4
98×101
645-180-245
简便运算
=
=
=
=
=
=
645-245-180
400-180
220
98×(100+1)
9800+98
9898
553-(289+153)
772-456+228
简便运算
=
=
=
=
=
=
553-153
400-289
111
772+228
-456
1000-456
544
-289
85×102
简便运算
=
=
=
=
=
=
67×23+67×78+67-67
85×
67×
67×100
6700
8500+170
8670
(100+2)
(23+78-1)
78×98
65+65×99
简便运算
=
=
=
=
=
=
78×
7800-78×2
7800-156
=7644
65×(1+99)
65×100
6500
(100-2)
5×87+87+87×4
456-273-127
简便运算
=
=
=
=
=
=
87×(5+4+1)
87×10
870
456-
456-400
56
(273+127)
623-169-223
650+(171+350)+129
简便运算
=
=
=
=
=
=
623-223-169
600-169
431
(650+350)
+(171+129 )
1300
1000+300
128+114+86+172
125×72
简便运算
=
=
=
=
=
=
(128+172)
+(114+86)
200+200
400
125
1000×9
9000
×8×9
1300÷91×7
=1300×7
=9100
=100
1300÷91×7
=1300
=1300
=100
÷91
÷91
÷(91÷7)
÷13
点睛:
①计算符号与数的亲密关系
②添括号后计算符号在什么情况下会发生变化
简便运算
63×55+35×81
=63×55
=63×55
=63×
=6300
+5×7
×9×9
+63
×45
(55+45)
点睛:
拆数重组后再用乘法分配律
简便运算
45×54+70×81
=5×9
×9×6
+70×81
=30×81
+70×81
=100×81
=8100
点睛:
拆数重组后再用乘法分配律
简便运算
63×52+42×72
=63×52+
=63×52+
=63×
=6300
6×7×
8×9
63
×48
(52+48)
点睛:
拆数重组后再用乘法分配律
96×96-97×95
=96×96
-(96+1)
×95
=96×96
=96×
-96×95
-95
-95
=96-95
=1
(96-95)
点睛:
拆数重组后再用乘法分配律
四年级简便运算
1999+999×999
=1000+ 999
+999×999
=1000+
=1000+
=1000
=1000000
999×(1+999)
999×1000
+ 999000
点睛:
拆数重组后再用乘法分配律
简便运算
25×182+26×218
=
25×182+(25+1)×218
=25×182
+25×218
+218
=25×400+218
=10218
点睛:
拆数相加再用乘法分配律
(465+654+546)÷15
555
=(444+
=(111×4
=111×
=111×(15÷15)
=111
+666)
÷15
+111×5
+111×6)
÷15
(4+5+6)
÷15
点睛:
拆数重组后再用乘法分配律
25×(981+983+987+989)
=25×(900×4+80×4+5×4)
=25×4×985
=100×985
25×(981+983+987+989)
=25×(4000-19-17-13-11)
=25×4000-25×60
=98500
=98500
=25×(4000-60)
拆数重组后再用乘法分配律
点睛:
25×182+26×218
=25×182+
25×218
+218
=25×(182+218)
=25×400+218
=10000+218
=10218
+218
点睛:
拆数重组后再用乘法分配律
25×(981+983+987+989)
=25×(
=25×
=100
=98500
百十 个
9 8 1
9 8 3
9 8 7
9 8 9
20
900×4
+80×4
+5×4)

(900+80+5)
×985
点睛:
拆分重组后再用乘法分配律
44×25+88×76
=
(88-44)
=
=
=
×25
+88×76
88×25
+88×76
-44×25
88×(25+76)
-11×4×25
88×101
-11×100
=8888
-1100
=7788

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