Explanation:
Let’s solve each part step by step. Remember:
- When adding or subtracting time, handle
hours and
minutes separately.
- If minutes go over 60 when adding, convert the extra 60 minutes to 1 hour.
- If minutes go below 0 when subtracting, borrow 1 hour (which is 60 minutes) from the hours.
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1. Adding times
a) 4 hr 15 min + 3 hr 20 min
Hours: 4 + 3 = 7 hr
Minutes: 15 + 20 = 35 min
→ Total:
7 hr 35 min
b) 6 hr 25 min + 3 hr 30 min
Hours: 6 + 3 = 9 hr
Minutes: 25 + 30 = 55 min
→ Total:
9 hr 55 min
c) 3 hr 35 min + 2 hr 35 min
Hours: 3 + 2 = 5 hr
Minutes: 35 + 35 = 70 min
But 70 min = 1 hr 10 min
So add 1 hr to hours: 5 + 1 = 6 hr, and keep 10 min
→ Total:
6 hr 10 min
d) 8 hr 45 min + 5 hr 55 min
Hours: 8 + 5 = 13 hr
Minutes: 45 + 55 = 100 min
100 min = 1 hr 40 min
Add 1 hr: 13 + 1 = 14 hr, keep 40 min
→ Total:
14 hr 40 min
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2. Subtracting times
a) 6 hr 57 min − 2 hr 35 min
Hours: 6 − 2 = 4 hr
Minutes: 57 − 35 = 22 min
→ Total:
4 hr 22 min
b) 7 hr 48 min − 4 hr 37 min
Hours: 7 − 4 = 3 hr
Minutes: 48 − 37 = 11 min
→ Total:
3 hr 11 min
c) 9 hr 25 min − 5 hr 45 min
Minutes: 25 − 45 → can’t do that directly!
So borrow 1 hour = 60 min from 9 hr → becomes 8 hr, and minutes become 25 + 60 = 85 min
Now: 85 − 45 = 40 min
Hours: 8 − 5 = 3 hr
→ Total:
3 hr 40 min
d) 11 hr 12 min − 1 hr 54 min
Minutes: 12 − 54 → can’t do directly.
Borrow 1 hr = 60 min from 11 hr → becomes 10 hr, minutes = 12 + 60 = 72 min
Now: 72 − 54 = 18 min
Hours: 10 − 1 = 9 hr
→ Total:
9 hr 18 min
Let me double-check all:
1a) 4:15 + 3:20 = 7:35
✔
1b) 6:25 + 3:30 = 9:55
✔
1c) 3:35 + 2:35 = 6:10
✔ (35+35=70→1h10m)
1d) 8:45 + 5:55 = 14:40
✔ (45+55=100→1h40m; 8+5+1=14)
2a) 6:57 − 2:35 = 4:22
✔
2b) 7:48 − 4:37 = 3:11
✔
2c) 9:25 − 5:45 → borrow → 8:85 − 5:45 = 3:40
✔
2d) 11:12 − 1:54 → borrow → 10:72 − 1:54 = 9:18
✔
All correct.
Final Answer:
1a) 7 hr 35 min
1b) 9 hr 55 min
1c) 6 hr 10 min
1d) 14 hr 40 min
2a) 4 hr 22 min
2b) 3 hr 11 min
2c) 3 hr 40 min
2d) 9 hr 18 min
Parent Tip: Review the logic above to help your child master the concept of time addition worksheet.
