Adding and Subtracting Decimals Practice Questions

To review these concepts, go to Adding and Subtracting Decimals Study Guide.

Adding and Subtracting Decimals Practice Questions

Practice

Where should the decimal point be placed in each sum?

1. 3.5 + 3.7 = 72
2. 1.4 + 0.8 = 22
3. 1.79 + 0.21 = 200
4. 4.13 + 2.07 + 5.91 = 1211
5. 4.835 + 1.217 = 6052
6. 9.32 + 4.1 = 1342
7. 7.42 + 125.931 = 133351
8. 6.1 + 0.28 + 4 = 1038

Add the following decimals.

9. 1.789 + 0.219
10. 1.48 + 0.9
11. 3.59 + 6
12. 10.7 + 8.935
13. 6.1 + 0.2908 + 4
14. 14.004 + 0.9 + 0.21
15. 1.03 + 2.5 + 40.016
16. 5.2 + 0.7999 + 0.0001

Subtract the following decimals.

17. 6.4 – 1.3
18. 1.89 – 0.37
19. 12.35 – 8.05
20. 2.35 – 0.9
21. 5 – 3.81
22. 3.2 – 1.23
23. 1 – 0.98765
24. 2.4 – 2.3999

Add and subtract the following decimals.

25. 6.4 – 1.3 + 1.2
26. 8.7 – 3.2 + 4
27. 5.48 + 0.448 – 0.24
28. 7 – 0.3 – 3.1 + 3.8
29. 4.7 + 2.41 – 0.8 – 1.77
30. 1 – 0.483 + 3.17
31. 14 – 0.15 + 0.8 – 0.2
32. 22.2 – 3.3 – 4.4 – 5.5

Word Problems Practice

Word problems 33–40 involve decimal addition, subtraction, and rounding.

33. At the supermarket, Alberto purchased 2.3 pounds of tomatoes, 1.1 pounds of lettuce, a 0.6 pound cucumber, and 4 pounds of carrots. He also decided to buy 1.2 pounds of bananas. How many pounds of produce did Alberto buy?

    a. 5.2

    b. 8.1

    c. 9.2

    d. 10.4

    e. 12.8

34. Janice improved her time running a mile in track from 6.3 minutes to 5.66 minutes. By how much time did she improve?

    a. 0.36 minute

    b. 0.64 minute

    c. 0.76 minute

    d. 1.23 minutes

    e. 1.36 minutes

35. John loaned Alexis $70.28 on Friday, and on Saturday, Alexis thanked him by paying him back $75. How much extra money did Alexis give to John?

    a. $5.28

    b. $4.72

    c. $4.28

    d. $4.72

    e. $4.82

36. Joseph had a credit card balance of $278.24 at the beginning of the month. He bought some clothes for $135.30 and a television for $221.28. At the end of the month, he made a payment of $350. How much money is needed to pay off his debt completely?

    a. $273.82

    b. $283.82

    c. $284.82

    d. $634.82

    e. $984.82

37. Karin bought three books for $8.95 each and two magazines for $1.49 each. How much did she spend in total?

    a. $29.83

    b. $26.83

    c. $29.94

    d. $27.83

    e. $28.94

38. Matt bought some used records and CDs that cost $6.99, $12.49, $8.50, and $11.89. The cashier told him the total was $39.87.Was this reasonable? Why or why not?
39. John walked 1.4 miles to work, 0.7 miles to lunch, and 0.8 miles to the store. Cindy ran 3.6 miles for exercise at the local track. Who covered more distance? By how much?
40. Brand A's road bike weighs 22.5 pounds, and brand B's bike weighs 22.15 pounds. Which one is lighter? By how much?

Add Decimals and Fractions Practice

Solutions

1. 7.2
2. 2.2
3. 2.0
4. 12.11
5. 6.052
6. 13.42
7. 133.351
8. 10.38
9. 2.008
10. 2.38
11. 9.59
12. 19.635
13. 10.3908
14. 15.114
15. 43.546
16. 6
17. 5.1
18. 1.52
19. 4.3
20. 1.45
21. 1.19
22. 1.97
23. 0.01235
24. 0.0001
25. 6.3
26. 9.5
27. 5.688
28. 7.4
29. 4.54
30. 3.687
31. 14.45
32. 9 or 9.0
33. c.
34. b.
35. d.
36. c.
37. a.
38. Yes. Round the prices to nearest dollar and add them: $7 + $12 + $9 + $12 = $40.
39. Cindy, by 0.7 miles. John's distance was 1.4 + 0.7 + 0.8 = 2.9 miles. The extra distance that Cindy covered is 3.6 - 2.9 = 0.7 miles.
40. Brand B by 0.35 pounds.
41. 1
42. 0.5 or
43. 1.125 or
44. 5.2
45. 2.75 or
46. 1
47. 5.9 or
48. 
49.