运算定律练习题
(1)乘法交换律:a×b=b×a 乘法结合律:(a×b)×c=a×(b×c) 38×25×4 42×125×8 25×17×4 (25×125)×(8×4)
49×4×5 38×125×8×3 (125×25)×4
5 ×289×2 (125×12)×8 125×(12×4)
(2) 乘法交换律和结合律的变化练习
125×64 125×88 44×25 125×24 25×28
3)加法交换律:a+b=b+a 加法结合律:(a+b)+c=a+(b+c)
357+288+143 158+395+105 167+289+33 129+235+171+165
378+527+73 169+78+22 58+39+42+61 138+293+62+107
(4)乘法分配律:(a+b)×c=a×c+b×c 正用练习
(80+4)×25 (20+4)×25 (125+17)×8 25×(40+4) 15×(20+3)
(5)乘法分配律正用的变化练习: 36×3 25×41 39×101 125×88 201×24
(6)乘法分配律反用的练习:
34×72+34×28 35×37+65×37 85×82+85×18
25×97+25×3 76×25+25×24
(7)乘法分配律反用的变化练习:
38×29+38 75×299+75 64×199+64 35×68+68+68×64
☆思考题:(8)其他的一些简便运算。
800÷25 6000÷125 3600÷8÷5
58×101-58 74×99
【思路导航】在除法里,被除数和除数同时乘或除以一个相同的数,商不变。 325÷25 =(325×4)÷(25×4) =1300÷100 =13 【练一练1】(1)450÷25 (2)525÷25 (3)3500÷125
(4)10000÷625 (5)49500÷900 (6)9000÷225
【经典例题二】计算25×125×4×8
【思路导航】如果先把25与4相乘,可以得到100,同时把125与8相乘,可以得到1000;再把100和1000相乘就可以了。运用了乘法交换律和结合律。 25×125×4×8 =(25×4)×(125×8) =100×1000 =100000 【练一练2】(1)125×15×8×4 (2)25×24 (3)125×16
(4)75×16 (5)125×25×32 (6)25×5×64×125
【经典例题三】计算:(1)125×34+125×66 (2)43×11+43×36+43×52+43 【思路导航】利用乘法分配律来计算这两题 (1)125×34+125×66 (2)43×11+43×36+43×52+43 =125×(34+66) =43×(11+36+52+1)
=125×100 =43×100 =12500 =4300 【练一练3】计算下面各题: (1)125×64+125×36 (2)64×45+64×71-64×16 (3)21×73+26×21+21
【经典例题四】计算(1)(360+108)÷36 (2)1÷2+3÷2+5÷2+7÷2
【思路导航】两个数的和、差除以一个数,可以用这个数分别去除这两个数,再求出两个商的和(差)。利用这一性质,可以使计算简便。 (1)(360+108)÷36 (2)1÷2+3÷2+5÷2+7÷2 =360÷36+108÷36 =(1+3+5+7)÷2 =10+3 =16÷2 =13 =8 【练一练4】(1)(720+96)÷24 (2)(4500-90)÷45 (3)6342÷21
(4)8811÷89 (5)73÷36+105÷36+146÷36 (6)(10000-1000-100-10)÷10
【经典例题五】
158×
61÷
79×
3
【思路导航】在乘除混合运算中,如果算式中没有括号,计算式可以根据运算定律和性质调
换乘数或者除数的位置,只要计算:数字跟着前面的符号一起移动。
【经典例题五】158×61÷79×3
【思路导航】在乘除混合运算中,如果算式中没有括号,计算式可以根据运算定律和性质调换乘数或者除数的位置,只要计算:数字跟着前面的符号一起移动。 158×61÷79×3 =158÷79×61×3 =2×61×3 =366
【练一练5】计算下面各题: (1)238×36÷119×5 (2)138×27÷69×50
(3)624×48÷312÷8 (4)406×312÷104÷203
【经典例题六】计算下面各题: (1)103×96÷16 (2)200÷(25÷4)
【思路导航】这两道题都是乘除法混合运算,我们可以根据这两道题的特点,采用加括号和去括号的方法,使计算简便。可以概括为:括号前是乘号,加、去括号不改号,括号前是除
号,田、去括号要改号。 (1)103×96÷16 (2)200÷(25÷4) =103×(96÷16) =200÷25×4 =103×6 =8×4
=618 =32 【练一练6】计算下面各题: (1)612×366÷183 (2)1000÷(125÷4)
(3)(13×8×5×6)÷(4×5×6) (4)241×345÷678÷345×(678÷241)
【经典例题七】计算:(1)68×62 (2)85×85
【思路导航】这两题的形式叫做“头同尾合十”它们的计算方法是:先用两个因数的个位数相乘,并把积直接写在末尾,如果积不满10,十位上要补写0,然后再将两个因数的十位数乘它本身加1的和,积写在两个个位数积的前面。 (1)68×62 第一步8×2=16,第二步6×(6+1)=42,合起来是4216 (2)85×85 第一步5×5=25,第二步是8×(8+1)=72,合起来是7225 【练一练7】(1)23×27 (2)46×44 (3)55×55 (4)91×99
【经典例题八】计算:26×11
【思路导航】一个两位数乘11的方法是:用两位数的头作积的头,用两位数的尾作积的尾,用这个两位数的两个数字之和作积的中间数(如果相加满十,则把和的十位数“1”加到头上。
26×11
第一步2作积的头,第二步6作积的尾,第三步2+6=8作中间,合起来是286。 【练一练8】计算(1)53×11 (2)39×11 (3)65×11 (4)98×11
【经典例题九】计算:358×11
【思路导航】三位数乘11,用三位数的头作积的头,用三位数的尾作积的尾,用三位数前两位数字组成的数加厚两位数字组成的数的和作积的中间数。 358×11,第一步用3作积的头,第二步用8作积的尾,在用35+58=93,合起来是3938。 【练一练9】计算(1)353×11 (2)654×11 (3)896×11
【练一练1】(1)450÷25 (2)525÷25 (3)3500÷125
4)10000÷625 (5)49500÷900 (6)9000÷225
【练一练2】(1)125×15×8×4 (2)25×24 (3)125×16
(4)75×16 (5)125×25×32 (6)25×5×64×125
【练一练3】计算下面各题: (1)125×64+125×36 (2)64×45+64×71-64×16 (3)21×73+26×21+21
【练一练4】(1)(720+96)÷24 (2)(4500-90)÷45 (3)6342÷21
(4)8811÷89 (5)73÷36+105÷36+146÷36 (6)(10000-1000-100-10)÷10
【练一练5】计算下面各题: (1)238×36÷119×5 (2)138×27÷69×50
(3)624×48÷312÷8 (4)406×312÷104÷203
【练一练6】计算下面各题: (1)612×366÷183 (2)1000÷(125÷4)
(3)(13×8×5×6)÷(4×5×6) (4)241×345÷678÷345×(678÷241)
【练一练7】(1)23×27 (2)46×44 (3)55×55 (4)91×99
【练一练8】计算(1)53×11 (2)39×11 (3)65×11 (4)98×11
【练一练9】计算(1)353×11 (2)654×11 (3)896×11
简便计算专题训练
158+262+138 375+219+381+225 5001-247-1021-232
(181+2564)+2719 378+44+114+242+222 276+228+353+219
(375+1034)+(966+125) (2130+783+270)+1017 99+999+9999+99999
7755-(2187+755) 2214+638+286 3065-738-1065
158+262+138 375+219+381+225 5001-247-1021-232
(181+2564)+2719 378+44+114+242+222 276+228+353+219
(375+1034)+(966+125) (2130+783+270)+1017 99+999+9999+99999
7755-(2187+755) 2214+638+286 3065-738-1065
1883-398 12×25 75×24
138×25×4 (13×125)×(3×8) (12+24+80)×50
希望可以帮到你O(∩_∩)O哈哈~
12 –5 = 11 – 4 = 13 – 8 = 13 –6 =
17 – 9 =
12 – 8 = 59 – 25 = 62 – 40 = 40 – 28 = 19 + 26 =
49 + 37 =
46 + 35 = 33 + 58 – 24 = 24 + 61 – 39 = 22 + 39 – 47 = 47 – 18 + 25 = 52 – 48 + 76 = 88 – 41 + 35 = 86 – 29 – 12 =
71 – 28 – 23 =
99 – 73 – 25 =
练习2
14 –5 = 18 – 9 = 14 – 8 = 15 –8 =
16 – 9 =
11 – 8 = 30 – 13 = 29 – 24 = 63 – 25 = 37 + 15 =
14 + 15 =
24 + 17 = 15 + 36 + 14 = 68 + 13 + 14 = 55 + 19 + 27 = 32 + 57 – 23 = 23 + 60 – 38 = 11 + 38 – 46 = 46 – 17 + 24 =
51 – 47 + 75 =
77 – 41 + 34 =
练习3
16 –9 = 15 – 9 = 15 – 7 = 12 –3 =
11 – 4 =
13 – 5 = 38 – 25 = 37 – 22 = 56 – 48 = 19 + 26 =
16 + 77 =
46 + 35 = 85 – 28 – 11 = 70 – 27 – 22 = 88 – 72 – 12 = 14 + 35 + 13 = 67 + 12 + 13 = 44 + 19 + 26 = 34 + 59 – 25 =
25 + 62 – 40 =
23 + 40 – 48 =
练习4
13 –4 = 14 – 6 = 16 – 8 = 22 –5 =
22 – 4 =
23 – 8 = 59 – 35 = 63 – 40 = 40 – 38 = 29 + 36 =
49 + 37 =
46 + 35 = 48 – 19 + 26 = 53 – 49 + 77 = 99 – 41 + 35 = 87 – 30 – 13 = 72 – 29 – 24 = 84 – 13 – 25 = 16 + 37 + 15 =
69 + 14 + 15 =
56 + 20 + 17 =
练习5
23 –6 = 27 – 9 = 22 – 8 = 24 –5 =
28 – 9 =
24 – 8 = 30 – 23 = 39 – 34 = 63 – 35 = 37 + 25 =
24 + 25 =
34 + 27 = 24 + 38 – 25 = 25 + 37 – 40 = 13 + 58 – 48 = 47 – 19 + 26 = 53 – 16 + 77 = 70 – 41 + 35 = 65 – 28 – 13 =
72 – 25 – 24 =
62 – 13 – 25 =
练习6
25 –8 = 26 – 9 = 22 – 8 = 26 –9 =
25 – 9 =
25 – 7 = 38 – 35 = 37 – 33 = 56 – 48 = 29 + 36 =
26 + 77 =
46 + 35 = 24 + 37 + 15 = 69 + 13 + 15 = 56 + 19 + 17 = 33 + 58 – 34 = 34 + 62 – 39 = 33 + 39 – 47 = 47 – 28 + 35 =
53 – 48 + 76 =
88 – 42 + 35 =
练习7 22 –3 = 22 – 4 = 23 – 5 = 23 –4 =
24 – 6 =
26 – 8 = 38 – 23 = 53 – 34 = 33 – 35 = 37 + 25 =
28 + 25 =
29 + 27 = 86 – 39 – 23 = 72 – 38 – 33 = 99 – 53 – 35 = 25 + 36 + 24 = 48 + 23 + 24 = 33 + 29 + 37 = 33 + 57 – 33 =
33 + 60 – 38 =
22 + 38 – 46 =
练习8
23 –5 = 22 – 4 = 23 – 8 = 23 –6 = 27 – 9 = 23 – 8 = 24 –5 = 28 – 9 = 24 – 8 = 25 –8 26 – 9 =
22 – 8 = 46 – 27 + 34 = 52 – 47 + 75 = 77 – 42 + 34 = 85 – 38 – 22 = 70 – 37 – 33 = 88 – 43 – 23 = 24 + 35 + 23 =
47 + 23 + 23 = 24 + 29 + 36 =
练习9
26 –9 = 25 – 9 = 25 – 7 = 23 –3 = 22 – 4 = 23 – 5 = 23 –4 = 24 – 6 = 26 – 8 = 33 –5 = 33 – 4 =
33 – 8 = 34 + 59 – 35 = 35 + 63 – 40 = 33 + 40 – 48 = 48 – 29 + 36 = 53 – 49 + 77 = 99 – 42 + 35 = 87 – 30 – 23 = 73 – 39 – 34 = 84 – 23 – 35 = 65 – 38 – 23 =
73 – 15 – 34 = 63 – 23 – 35 =
练习10
33 –6 = 37 – 9 = 33 – 8 = 34 –5 = 38 – 9 = 34 – 8 = 35 –8 = 36 – 9 = 33 – 8 = 36 –9 = 35 – 9 = 35 – 7 =
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