Let’s solve each problem step by step. We’ll add or subtract hours and minutes separately, and remember:
→ 60 minutes = 1 hour
→ If minutes go over 60 when adding, convert the extra to hours.
→ If minutes are too small when subtracting, borrow 1 hour (which is 60 minutes).
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Problem 1:
7 hours 59 minutes + 3 hours 10 minutes
Add hours: 7 + 3 = 10 hours
Add minutes: 59 + 10 = 69 minutes → that’s 1 hour 9 minutes
So total: 10 hours + 1 hour 9 minutes =
11 hours 9 minutes
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Problem 2:
19 hours 9 minutes – 1 hour 42 minutes
We can’t subtract 42 minutes from 9 minutes, so we borrow 1 hour from 19 hours.
19 hours 9 minutes becomes 18 hours 69 minutes
Now subtract:
Hours: 18 – 1 = 17 hours
Minutes: 69 – 42 = 27 minutes
Answer:
17 hours 27 minutes
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Problem 3:
18 hours 6 minutes – 13 hours 25 minutes
Can’t subtract 25 minutes from 6 minutes → borrow 1 hour
18 hours 6 minutes becomes 17 hours 66 minutes
Subtract:
Hours: 17 – 13 = 4 hours
Minutes: 66 – 25 = 41 minutes
Answer:
4 hours 41 minutes
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Problem 4:
2 hours 38 minutes + 20 hours 33 minutes
Hours: 2 + 20 = 22 hours
Minutes: 38 + 33 = 71 minutes → that’s 1 hour 11 minutes
Total: 22 + 1 = 23 hours, plus 11 minutes →
23 hours 11 minutes
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Problem 5:
5 hours 40 minutes + 12 hours 52 minutes
Hours: 5 + 12 = 17 hours
Minutes: 40 + 52 = 92 minutes → that’s 1 hour 32 minutes
Total: 17 + 1 = 18 hours, plus 32 minutes →
18 hours 32 minutes
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Problem 6:
6 hours 17 minutes – 3 hours 27 minutes
Can’t subtract 27 minutes from 17 minutes → borrow 1 hour
6 hours 17 minutes becomes 5 hours 77 minutes
Subtract:
Hours: 5 – 3 = 2 hours
Minutes: 77 – 27 = 50 minutes
Answer:
2 hours 50 minutes
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Problem 7:
Allen took 2 hours 15 minutes for science project
and 3 hours 49 minutes for art project
Add them together:
Hours: 2 + 3 = 5 hours
Minutes: 15 + 49 = 64 minutes → that’s 1 hour 4 minutes
Total: 5 + 1 = 6 hours, plus 4 minutes →
6 hours 4 minutes
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Final Answer:
1) 11 hours 9 minutes
2) 17 hours 27 minutes
3) 4 hours 41 minutes
4) 23 hours 11 minutes
5) 18 hours 32 minutes
6) 2 hours 50 minutes
7) 6 hours 4 minutes
Parent Tip: Review the logic above to help your child master the concept of addition of time worksheet.
