四年级下册数学计算题怎么学更高效？

分为基础巩固和挑战提升两个部分，并附有详细的答案与解析，方便孩子检查和订正。

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第一部分：基础巩固 (必会计算)

这部分主要考察孩子对基本计算法则的掌握情况。

四则混合运算 (注意运算顺序)

1. 25 + 15 × 4
2. (25 + 15) × 4
3. 200 - 80 ÷ 2
4. (200 - 80) ÷ 2
5. 36 + 64 ÷ 8 - 5
6. 100 - (35 + 25) × 2
7. 72 ÷ 8 + 42 ÷ 7
8. 18 × (450 - 150) ÷ 5

小数的加减法 (注意小数点对齐)

1. 5 + 2.4 =
2. 8 - 5.6 =
3. 27 + 5.83 =
4. 05 - 4.35 =
5. 5 + 0.75 + 7.5 =
6. 10 - 3.8 - 2.2 =
7. 6 + 2.78 + 4.4 =
8. 15 - (8.54 + 1.46) =

解方程 (根据等式的性质求解)

1. x + 35 = 100
2. x - 18 = 27
3. 5x = 45
4. x ÷ 9 = 12
5. x + 48 = 120
6. 3x = 150
7. x ÷ 6 = 13
8. x - 27 = 90

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第二部分：挑战提升 (简便运算与综合应用)

这部分考察孩子对运算定律的灵活运用和综合解决问题的能力。

简便运算 (运用加法/乘法交换律、结合律、分配律)

1. 25 + 37 + 75 + 63
2. 125 × 8 × 4
3. 25 × 16 (提示：16 = 4 × 4)
4. 99 × 25 + 25 (提示：把25看作 1 × 25)
5. 18 × 102 (提示：102 = 100 + 2)
6. 8 + 3.7 + 5.2
7. 5 - 3.86 - 6.14
8. 12 × 25 + 28 × 25

综合计算 (混合运算与简便运算结合)

1. 85 + 15 × 6 - 70
2. 320 ÷ 8 + 25 × 4
3. (200 - 50) × 4 ÷ 25
4. 125 × 32 (提示：32 = 8 × 4)
5. 99 × 101 (提示：101 = 100 + 1)

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答案与解析

第一部分：基础巩固

四则混合运算

1. 25 + 15 × 4 = 25 + 60 = 85
2. (25 + 15) × 4 = 40 × 4 = 160
3. 200 - 80 ÷ 2 = 200 - 40 = 160
4. (200 - 80) ÷ 2 = 120 ÷ 2 = 60
5. 36 + 64 ÷ 8 - 5 = 36 + 8 - 5 = 44 - 5 = 39
6. 100 - (35 + 25) × 2 = 100 - 60 × 2 = 100 - 120 = -20
7. 72 ÷ 8 + 42 ÷ 7 = 9 + 6 = 15
8. 18 × (450 - 150) ÷ 5 = 18 × 300 ÷ 5 = 5400 ÷ 5 = 1080

小数的加减法

1. 5 + 2.4 = 5.9
2. 8 - 5.6 = 5.2
3. 27 + 5.83 = 10.10 (注意：百分位相加满十，向十分位进一)
4. 05 - 4.35 = 4.70 (注意：十分位不够减，从个位借1当10)
5. 5 + 0.75 + 7.5 = (12.5 + 7.5) + 0.75 = 20 + 0.75 = 20.75 (运用加法交换律和结合律)
6. 10 - 3.8 - 2.2 = 10 - (3.8 + 2.2) = 10 - 6 = 4 (运用减法性质)
7. 6 + 2.78 + 4.4 = (5.6 + 4.4) + 2.78 = 10 + 2.78 = 12.78 (运用加法交换律和结合律)
8. 15 - (8.54 + 1.46) = 15 - 10 = 5 (先算括号里的)

解方程

1. x + 35 = 100 => x = 100 - 35 => x = 65
2. x - 18 = 27 => x = 27 + 18 => x = 45
3. 5x = 45 => x = 45 ÷ 5 => x = 9
4. x ÷ 9 = 12 => x = 12 × 9 => x = 108
5. x + 48 = 120 => x = 120 - 48 => x = 72
6. 3x = 150 => x = 150 ÷ 3 => x = 50
7. x ÷ 6 = 13 => x = 13 × 6 => x = 78
8. x - 27 = 90 => x = 90 + 27 => x = 117

第二部分：挑战提升

简便运算

1. 25 + 37 + 75 + 63 = (25 + 75) + (37 + 63) = 100 + 100 = 200
2. 125 × 8 × 4 = 125 × (8 × 4) = 125 × 32 = 4000
3. 25 × 16 = 25 × (4 × 4) = (25 × 4) × 4 = 100 × 4 = 400
4. 99 × 25 + 25 = (99 + 1) × 25 = 100 × 25 = 2500 (运用乘法分配律的逆运算)
5. 18 × 102 = 18 × (100 + 2) = 18 × 100 + 18 × 2 = 1800 + 36 = 1836 (运用乘法分配律)
6. 8 + 3.7 + 5.2 = (4.8 + 5.2) + 3.7 = 10 + 3.7 = 13.7
7. 5 - 3.86 - 6.14 = 12.5 - (3.86 + 6.14) = 12.5 - 10 = 2.5
8. 12 × 25 + 28 × 25 = (12 + 28) × 25 = 40 × 25 = 1000

综合计算

1. 85 + 15 × 6 - 70 = 85 + 90 - 70 = 175 - 70 = 105
2. 320 ÷ 8 + 25 × 4 = 40 + 100 = 140
3. (200 - 50) × 4 ÷ 25 = 150 × 4 ÷ 25 = 600 ÷ 25 = 24
4. 125 × 32 = 125 × (8 × 4) = (125 × 8) × 4 = 1000 × 4 = 4000
5. 99 × 101 = 99 × (100 + 1) = 99 × 100 + 99 × 1 = 9900 + 99 = 9999 能帮助四年级的同学巩固和提升计算能力！练习时一定要认真细心哦！