Math worksheet for practicing time calculations, including adding and subtracting minutes, determining time intervals, and finding missing times.

Let's solve each part of the worksheet step by step and explain the reasoning.

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1) Add on the minutes to each of these times:

We add the given minutes to each time. Remember:
- 60 minutes = 1 hour
- If minutes exceed 60, convert extra minutes into hours.

#### a) 3:20pm + 30 mins
3:20 + 30 = 3:50pm
✔ Answer: 3:50pm

#### b) 6:45pm + 15 mins
6:45 + 15 = 7:00pm (since 45 + 15 = 60 → 1 hour)
✔ Answer: 7:00pm

#### c) 8:15am + 25 mins
8:15 + 25 = 8:40am
✔ Answer: 8:40am

#### d) 2:50pm + 40 mins
2:50 + 40 = 3:30pm (50 + 40 = 90 mins = 1 hour 30 mins → 2:50 + 1h = 3:50, then subtract 20 mins? Wait — better:
2:50 + 10 mins = 3:00, then +30 more = 3:30pm
✔ Answer: 3:30pm

#### e) 11:35am + 50 mins
11:35 + 50 = 12:25pm (35 + 50 = 85 mins = 1 hour 25 mins → 11:35 + 1h = 12:35, but we only need 50 mins → 11:35 + 25 = 12:00, then +25 = 12:25)
Wait:
11:35 + 25 = 12:00 (exactly), then +25 more = 12:25
✔ Answer: 12:25pm

#### f) 7:40am + 35 mins
7:40 + 35 = 8:15am (40 + 35 = 75 mins = 1h 15m → 7:40 + 1h = 8:40, minus 25? No:
Better: 7:40 + 20 = 8:00, then +15 = 8:15
✔ Answer: 8:15am

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2) Subtract the minutes from each of these times:

Subtract minutes; if you go below zero, borrow 1 hour (60 minutes).

#### a) 10:40am – 20 mins
10:40 – 20 = 10:20am
✔ Answer: 10:20am

#### b) 2:50pm – 15 mins
2:50 – 15 = 2:35pm
✔ Answer: 2:35pm

#### c) 10:20pm – 30 mins
10:20 – 30 → can't subtract 30 from 20, so borrow 1 hour:
10:20 = 9:80 (9 hours 80 minutes)
9:80 – 30 = 9:50pm
✔ Answer: 9:50pm

#### d) 9:10am – 25 mins
9:10 – 25 → borrow 1 hour:
9:10 = 8:70
8:70 – 25 = 8:45am
✔ Answer: 8:45am

#### e) 12:15pm – 40 mins
12:15 – 40 → borrow 1 hour:
12:15 = 11:75
11:75 – 40 = 11:35am
✔ Answer: 11:35am

#### f) 1:35pm – 50 mins
1:35 – 50 → borrow:
1:35 = 12:95 (since 1pm = 12:60, so 12:60 + 35 = 12:95)
12:95 – 50 = 12:45pm
✔ Answer: 12:45pm

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3) Work out how long the time interval is.

We find the difference between two times.

#### a) 3:25pm to 3:45pm
3:45 – 3:25 = 20 minutes ✔ (given)

#### b) 4:30pm to 5:10pm
From 4:30 to 5:00 = 30 mins
From 5:00 to 5:10 = 10 mins
Total = 30 + 10 = 40 minutes
✔ Answer: 40 minutes

#### c) 10:25am to 11:00am
From 10:25 to 11:00 = 35 minutes
✔ Answer: 35 minutes

#### d) 12:50pm to 1:15pm
From 12:50 to 1:00 = 10 mins
From 1:00 to 1:15 = 15 mins
Total = 10 + 15 = 25 minutes
✔ Answer: 25 minutes

#### e) 7:25pm to 8:05pm
From 7:25 to 8:00 = 35 mins
From 8:00 to 8:05 = 5 mins
Total = 35 + 5 = 40 minutes
✔ Answer: 40 minutes

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4) Write in the missing time:

#### a) 25 minutes earlier than 9:40am
9:40 – 25 = 9:15am
✔ Answer: 9:15am

#### b) 30 minutes later than 7:35pm
7:35 + 30 = 8:05pm
✔ Answer: 8:05pm

#### c) 15 minutes later than 11:40am
11:40 + 15 = 11:55am
✔ Answer: 11:55am

#### d) 25 minutes earlier than 1:10pm
1:10 – 25 → borrow: 1:10 = 12:70
12:70 – 25 = 12:45pm
✔ Answer: 12:45pm

#### e) 50 minutes earlier than 10:25am
10:25 – 50 → borrow: 10:25 = 9:85
9:85 – 50 = 9:35am
✔ Answer: 9:35am

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✔ Final Answers:

#### 1) Add minutes:
a) 3:50pm
b) 7:00pm
c) 8:40am
d) 3:30pm
e) 12:25pm
f) 8:15am

#### 2) Subtract minutes:
a) 10:20am
b) 2:35pm
c) 9:50pm
d) 8:45am
e) 11:35am
f) 12:45pm

#### 3) Time intervals:
a) 20 minutes
b) 40 minutes
c) 35 minutes
d) 25 minutes
e) 40 minutes

#### 4) Missing times:
a) 9:15am
b) 8:05pm
c) 11:55am
d) 12:45pm
e) 9:35am

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