《简便计算》计算题练习
①常见乘法计算:
25×4=100 125×8=1000
②加法交换律简算例子: ③加法结合律简算例子:
50 98 50 488 40 60
=50 50 98 =488 (40 60)
=100 98 =488 100
=198 =588
④乘法交换律简算例子: ⑤乘法结合律简算例子:
25×56×4 99×125×8
=25×4×56 =99×(125×8)
=100×56 =99×1000
=5600 =99000
⑥加法交换律与结合律: ⑦乘法交换律与结合律:
65 28 35 72 25×125×4×8
=(65 35) (28 72) =(25×4)×(125×8)
=100 100 =100×1000
=200 =100000
⑧乘法分配律简算例子:
一、分解式 二、合并式
25×(40 4) 135×12—135×2
=25×40 25×4 =135×(12—2)
=1000 100 =135×10
=1100 =1350
三、特殊1 四、特殊2
99×256 256 45×102
=99×256 256×1 =45×(100 2)
=256×(99 1) =45×100 45×2
=256×100 =4500 90
=25600 =4590
五、特殊3 六、特殊4
99×26 35×8 35×6—4×35
=(100—1)×26 =35×(8 6—4)
=100×26—1×26 =35×10
=2600—26 =350
=2574
⑨连续减法简便运算例子:
528—65—35 528—89—128 528—(150 128)
=528—(65 35) =528—128—89 =528—128—150
=528—100 =400—89 =400—150
=428 =311 =250
⑩连续除法简便运算例子:
3200÷25÷4
=3200÷(25×4)
=3200÷100
=32
⑪其它简便运算例子:
256—58 44 250÷8×4
=256 44—58 =250×4÷8
=300—58 =1000÷8
=242 =125
1)125 ×(17 × 8)× 4
= 125×8×4×17
=1000×68
=68000
2)375 × 480 6250 × 48
=480×(375+625)
=480000
3)25 × 16 ×125
=25×2×8×125
=50000
4)13 × 99
=13×(100-1)
=1300-13
=1287
5)75000 ÷ 125 ÷ 15
=75×1000÷125÷15
=75÷15×1000÷125
=5×8
=40
6)7900 ÷ 4 ÷ 25
=7900÷(4×25)
=79
7)150 × 40 ÷ 50
=150÷50×40
=3×40
=120
8)5600 ÷(25 ×7)
=56×100÷25÷7
=56÷7×100÷25
=32
9)210 ÷ 42 × 6
=210÷7÷6×6
=30
10)39600 ÷ 25
=396×100÷25
=396×4
=1584
11)67 × 21 +18 × 21 85 × 79
=21×(67 18) 85×79
=21×85 85×79
=85×(21 79)
=8500
12)321 × 81 321 × 19
=321×(81 19)
=32100
13)222222 × 999999
=222222×(1000000-1)
=222222000000-222222
=222221777778
14)333333 × 333333
=111111×999999
=111111×(1000000-1)
=111111000000-111111
=111110888889
15)56000 ÷ (14000 ÷ 16)
=56000÷14000×16
=4×16
=64
16)654321 × 909090 654321×90909
=654321×999999
=654321×(100000-1)
=654321000000-654321
=654320345679
17)34 × 3535 -35 × 3434
=34×35×101-35×34×101
=0
18)27000 ÷ 125
=27×1000÷125
=27×8
=216
19)345345 ÷ 15015
=345×1001÷(15×1001)
=345÷15×1001÷1001
=23
20)347 358 352 349
=350×4-3 8 2-1
=1400 6
=1406
21)75 × 45 17 × 25
=25×3×45 17×25
=25×(135 17)
=25×152
=25×4×38
=3800
22) 599996 49997 3998 407 89
=600000 50000 4000-4-3-2 407 89
=65400 487
=65887
23)(48 × 75 ×81)÷(24 × 25 × 27)
=48 × 75 ×81÷24÷25÷27
=48÷24×75÷25×81÷27
=2×3×3
=18
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