20 道分数加减法练习题：带解题步骤和答案

1/4 + 5/8 = 7/8

To add fractions, we need to find a common denominator. In this case, the common denominator is 8. We multiply the numerator and denominator of 1/4 by 2 to get 2/8, and we leave 5/8 as it is. Then, we add the numerators: 2/8 + 5/8 = 7/8.

3/5 - 1/10 = 5/10

To subtract fractions, we also need to find a common denominator. In this case, the common denominator is 10. We multiply the numerator and denominator of 3/5 by 2 to get 6/10, and we multiply the numerator and denominator of 1/10 by 5 to get 5/50, which simplifies to 1/10. Then, we subtract the numerators: 6/10 - 1/10 = 5/10, which simplifies to 1/2.

7/8 + 1/3 = 23/24

To add fractions with different denominators, we need to find a common denominator. In this case, the common denominator is 24. We multiply the numerator and denominator of 7/8 by 3 to get 21/24, and we multiply the numerator and denominator of 1/3 by 8 to get 8/24. Then, we add the numerators: 21/24 + 8/24 = 29/24, which simplifies to 1 5/24.

2/3 - 5/6 = -1/6

To subtract fractions with different denominators, we need to find a common denominator. In this case, the common denominator is 6. We multiply the numerator and denominator of 2/3 by 2 to get 4/6, and we multiply the numerator and denominator of 5/6 by 1 to get 5/6. Then, we subtract the numerators: 4/6 - 5/6 = -1/6.

1/2 + 2/5 = 9/10

To add fractions with different denominators, we need to find a common denominator. In this case, the common denominator is 10. We multiply the numerator and denominator of 1/2 by 5 to get 5/10, and we multiply the numerator and denominator of 2/5 by 2 to get 4/10. Then, we add the numerators: 5/10 + 4/10 = 9/10.

3/4 - 1/8 = 5/8

To subtract fractions, we need to find a common denominator. In this case, the common denominator is 8. We multiply the numerator and denominator of 3/4 by 2 to get 6/8, and we multiply the numerator and denominator of 1/8 by 4 to get 4/32. Then, we subtract the numerators: 6/8 - 4/32 = 5/8.

2/5 + 7/10 = 9/10

To add fractions, we need to find a common denominator. In this case, the common denominator is 10. We multiply the numerator and denominator of 2/5 by 2 to get 4/10, and we leave 7/10 as it is. Then, we add the numerators: 4/10 + 7/10 = 11/10, which simplifies to 1 1/10.

1/3 - 1/6 = 1/6

To subtract fractions, we need to find a common denominator. In this case, the common denominator is 6. We multiply the numerator and denominator of 1/3 by 2 to get 2/6, and we leave 1/6 as it is. Then, we subtract the numerators: 2/6 - 1/6 = 1/6.

5/8 + 1/4 = 3/4

4/7 - 1/7 = 3/7

To subtract fractions, we don't need to find a common denominator if the denominators are the same. In this case, we can simply subtract the numerators: 4/7 - 1/7 = 3/7.

2/3 + 1/6 = 5/6

To add fractions, we need to find a common denominator. In this case, the common denominator is 6. We multiply the numerator and denominator of 2/3 by 2 to get 4/6, and we leave 1/6 as it is. Then, we add the numerators: 4/6 + 1/6 = 5/6.

5/6 - 1/3 = 1/2

To subtract fractions, we need to find a common denominator. In this case, the common denominator is 6. We multiply the numerator and denominator of 5/6 by 1 to get 5/6, and we multiply the numerator and denominator of 1/3 by 2 to get 2/6. Then, we subtract the numerators: 5/6 - 2/6 = 3/6, which simplifies to 1/2.

3/4 + 2/3 = 17/12

To add fractions with different denominators, we need to find a common denominator. In this case, the common denominator is 12. We multiply the numerator and denominator of 3/4 by 3 to get 9/12, and we multiply the numerator and denominator of 2/3 by 4 to get 8/12. Then, we add the numerators: 9/12 + 8/12 = 17/12.

5/8 - 1/4 = 3/8

To subtract fractions, we need to find a common denominator. In this case, the common denominator is 8. We multiply the numerator and denominator of 5/8 by 1 to get 5/8, and we multiply the numerator and denominator of 1/4 by 2 to get 2/8. Then, we subtract the numerators: 5/8 - 2/8 = 3/8.

1/2 + 1/3 = 5/6

To add fractions, we need to find a common denominator. In this case, the common denominator is 6. We multiply the numerator and denominator of 1/2 by 3 to get 3/6, and we multiply the numerator and denominator of 1/3 by 2 to get 2/6. Then, we add the numerators: 3/6 + 2/6 = 5/6.

2/7 - 1/5 = 3/35

To subtract fractions, we need to find a common denominator. In this case, the common denominator is 35. We multiply the numerator and denominator of 2/7 by 5 to get 10/35, and we multiply the numerator and denominator of 1/5 by 7 to get 7/35. Then, we subtract the numerators: 10/35 - 7/35 = 3/35.

3/4 + 1/8 = 7/8

To add fractions, we need to find a common denominator. In this case, the common denominator is 8. We multiply the numerator and denominator of 3/4 by 2 to get 6/8, and we multiply the numerator and denominator of 1/8 by 1 to get 1/8. Then, we add the numerators: 6/8 + 1/8 = 7/8.

5/6 - 2/3 = 1/6

To subtract fractions, we need to find a common denominator. In this case, the common denominator is 6. We multiply the numerator and denominator of 5/6 by 1 to get 5/6, and we multiply the numerator and denominator of 2/3 by 2 to get 4/6. Then, we subtract the numerators: 5/6 - 4/6 = 1/6.

1/5 + 1/10 = 3/10

To add fractions, we need to find a common denominator. In this case, the common denominator is 10. We multiply the numerator and denominator of 1/5 by 2 to get 2/10, and we leave 1/10 as it is. Then, we add the numerators: 2/10 + 1/10 = 3/10.

3/8 - 1/6 = 5/24

To subtract fractions, we need to find a common denominator. In this case, the common denominator is 24. We multiply the numerator and denominator of 3/8 by 3 to get 9/24, and we multiply the numerator and denominator of 1/6 by 4 to get 4/24. Then, we subtract the numerators: 9/24 - 4/24 = 5/24.