Let’s solve each problem step by step. We’ll add hours, minutes, and seconds separately — but remember:
→ 60 seconds = 1 minute
→ 60 minutes = 1 hour
We’ll start with Part I.
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Part I: Find the sum of the following
Problem 1:
3 hr 17 min 24 sec + 4 hr 32 min 14 sec
Add seconds: 24 + 14 =
38 sec → no carryover
Add minutes: 17 + 32 =
49 min → no carryover
Add hours: 3 + 4 =
7 hr
✔ Answer:
7 hr 49 min 38 sec
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Problem 2:
6 hr 10 min 31 sec + 7 hr 38 min 05 sec
Seconds: 31 + 5 =
36 sec
Minutes: 10 + 38 =
48 min
Hours: 6 + 7 =
13 hr
✔ Answer:
13 hr 48 min 36 sec
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Problem 3:
2 hr 15 min 10 sec + 4 hr 20 min 27 sec
Seconds: 10 + 27 =
37 sec
Minutes: 15 + 20 =
35 min
Hours: 2 + 4 =
6 hr
✔ Answer:
6 hr 35 min 37 sec
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Problem 4:
4 hr 35 min 28 sec + 3 hr 16 min 26 sec
Seconds: 28 + 26 =
54 sec → still under 60, so no carryover
Minutes: 35 + 16 =
51 min → still under 60
Hours: 4 + 3 =
7 hr
✔ Answer:
7 hr 51 min 54 sec
Wait — let me double-check Problem 4:
28 + 26 = 54 → correct
35 + 16 = 51 → correct
4 + 3 = 7 → correct
No carryovers needed.
✔
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Now Part II: Add the given time.
(i) 24 minutes 42 seconds and 27 minutes 11 seconds
Seconds: 42 + 11 =
53 sec
Minutes: 24 + 27 =
51 min
✔ Answer:
51 min 53 sec
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(ii) 32 minutes 19 seconds and 20 minutes 53 seconds
Seconds: 19 + 53 =
72 sec → that’s more than 60!
So, 72 sec = 1 min 12 sec → write down 12 sec, carry over 1 min
Minutes: 32 + 20 = 52, plus carried 1 =
53 min
✔ Answer:
53 min 12 sec
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(iii) 6 years 8 months and 7 years 3 months
Months: 8 + 3 =
11 months → less than 12, so no carryover
Years: 6 + 7 =
13 years
✔ Answer:
13 years 11 months
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(iv) 10 years 5 months and 12 years 9 months
Months: 5 + 9 =
14 months → that’s more than 12!
14 months = 1 year 2 months → write down 2 months, carry over 1 year
Years: 10 + 12 = 22, plus carried 1 =
23 years
✔ Answer:
23 years 2 months
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All problems solved carefully. Let’s list final answers clearly.
Final Answer:
I.
1. 7 hr 49 min 38 sec
2. 13 hr 48 min 36 sec
3. 6 hr 35 min 37 sec
4. 7 hr 51 min 54 sec
II.
(i) 51 min 53 sec
(ii) 53 min 12 sec
(iii) 13 years 11 months
(iv) 23 years 2 months
Parent Tip: Review the logic above to help your child master the concept of time addition worksheet.
