Grade: Grade 3 Subject: Mathematics Unit: Measurement Conversions SAT: ProblemSolving+DataAnalysis ACT: Math

Time Conversions

Time is everywhere in our lives! From knowing when recess starts to figuring out how long until your birthday, understanding time helps us plan our days. Let's learn how to convert between different units of time!

Understanding Units of Time

Time Comes in Different Sizes!

Just like we use different rulers for different jobs, we use different units to measure time. Seconds for quick things, minutes for short activities, hours for longer events, and days for even bigger chunks of time!

Minutes to Hours
60
minutes
=
1
hour
Hours to Days
24
hours
=
1
day
Days to Weeks
7
days
=
1
week
Seconds to Minutes
60
seconds
=
1
minute
Memory Trick: Both minutes and seconds use the number 60! There are 60 seconds in a minute AND 60 minutes in an hour. That's easy to remember!

Converting Minutes to Hours

60 The Magic Number: 60

Since there are 60 minutes in 1 hour, we can use division and multiplication to convert between them!

  • Minutes to Hours: Divide by 60
  • Hours to Minutes: Multiply by 60

1 Example: Converting 120 Minutes to Hours

120 minutes = ? hours

  1. We know: 60 minutes = 1 hour
  2. Divide: 120 / 60 = 2
  3. So: 120 minutes = 2 hours

Answer: 2 hours

2 Example: Converting 3 Hours to Minutes

3 hours = ? minutes

  1. We know: 1 hour = 60 minutes
  2. Multiply: 3 x 60 = 180
  3. So: 3 hours = 180 minutes

Answer: 180 minutes

Quick Reference: Minutes and Hours

Minutes Hours Think of it as...
30 1/2 hour Half an hour
60 1 hour One full hour
90 1 1/2 hours An hour and a half
120 2 hours Two full hours
180 3 hours Three full hours
240 4 hours Four full hours

Converting Hours to Days

24 A Day Has 24 Hours

A full day - from midnight to the next midnight - has exactly 24 hours. This is true every single day!

  • Hours to Days: Divide by 24
  • Days to Hours: Multiply by 24

1 Example: Converting 48 Hours to Days

48 hours = ? days

  1. We know: 24 hours = 1 day
  2. Divide: 48 / 24 = 2
  3. So: 48 hours = 2 days

Answer: 2 days

2 Example: Converting 3 Days to Hours

3 days = ? hours

  1. We know: 1 day = 24 hours
  2. Multiply: 3 x 24 = 72
  3. So: 3 days = 72 hours

Answer: 72 hours

Quick Reference: Hours and Days

Hours Days Think of it as...
12 1/2 day Half a day
24 1 day One full day
48 2 days A whole weekend!
72 3 days Three full days
168 7 days One whole week!

Understanding Elapsed Time

What is Elapsed Time?

Elapsed time is the amount of time that passes between a start time and an end time. It answers the question: "How long did it take?"

1 Counting On Method

Start at the beginning time and count forward to the end time. This is great for shorter time periods!

Movie starts at 2:00 PM, ends at 4:30 PM. How long is the movie?

  1. Start at 2:00 PM
  2. Count 2 hours to get to 4:00 PM
  3. Count 30 more minutes to get to 4:30 PM
  4. Total: 2 hours + 30 minutes = 2 hours 30 minutes

Answer: 2 hours and 30 minutes

2 Number Line Method

Draw a timeline and hop from start to end!

School starts at 8:15 AM and ends at 3:15 PM. How long is the school day?

  1. From 8:15 AM to 12:15 PM = 4 hours (morning)
  2. From 12:15 PM to 3:15 PM = 3 hours (afternoon)
  3. Total: 4 + 3 = 7 hours

Answer: 7 hours

Interactive Elapsed Time Clock

See how elapsed time works! Watch the clocks show start and end times.

Start Time
12 1 2 3 4 5 6 7 8 9 10 11
3:00
End Time
12 1 2 3 4 5 6 7 8 9 10 11
5:30
Elapsed Time: 2 hours 30 minutes
Helpful Hint: When finding elapsed time, it can help to first count to the nearest hour, then continue counting. For example, from 2:45 to 5:00, first count 15 minutes to get to 3:00, then count 2 more hours to 5:00. Total: 2 hours 15 minutes!

Solving Time Word Problems

* Steps to Solve Time Word Problems

  1. Read carefully - What is the question asking?
  2. Find the important information - What times or durations are given?
  3. Choose your strategy - Will you add, subtract, or convert?
  4. Solve and check - Does your answer make sense?

Word Problem 1

Emma started reading her book at 4:15 PM. She read for 45 minutes. What time did she finish reading?
  1. Start time: 4:15 PM
  2. Add 45 minutes to 4:15
  3. 4:15 + 45 minutes = 5:00 PM

Answer: Emma finished at 5:00 PM

Word Problem 2

The soccer practice lasted 90 minutes. How many hours and minutes is that?
  1. We know 60 minutes = 1 hour
  2. 90 minutes = 60 minutes + 30 minutes
  3. 90 minutes = 1 hour + 30 minutes

Answer: 1 hour and 30 minutes

Word Problem 3

Jake's family is going on a trip that takes 3 days. How many hours will they be traveling?
  1. We know 1 day = 24 hours
  2. 3 days = 3 x 24 hours
  3. 3 x 24 = 72 hours

Answer: 72 hours

Try It Yourself: Time Converter

Use this tool to practice converting between different units of time!

Minutes and Hours Converter

minutes = 0 hours 0 minutes

Hours and Days Converter

hours = 0 days 0 hours

Practice Problems

Test your time conversion skills! Click the correct answer for each problem.

Your Score

0 / 0

Problem 1: Minutes to Hours

How many hours is 180 minutes?

Problem 2: Hours to Days

How many days is 72 hours?

Problem 3: Elapsed Time

A movie starts at 2:30 PM and ends at 4:45 PM.
How long is the movie?

Problem 4: Word Problem

Sam practiced piano for 2 hours.
How many minutes did he practice?

Problem 5: Converting Days to Hours

How many hours are in 2 days?

Problem 6: Mixed Units

75 minutes equals how many hours and minutes?

Problem 7: Finding End Time

Lunch starts at 11:45 AM and lasts 30 minutes.
What time does lunch end?

Problem 8: Challenge Problem

A road trip takes 5 hours and 30 minutes.
How many minutes is that in total?

Check Your Understanding

How many minutes are in 1 hour?

How many hours are in 1 day?

What is "elapsed time"?

What We Learned

60

Minutes & Hours

60 minutes = 1 hour

24

Hours & Days

24 hours = 1 day

+

Elapsed Time

Count from start to end to find how long

?

Word Problems

Read carefully and choose the right operation

Keep Practicing! Time conversions are used every day in real life. Practice by figuring out how long until dinner, how many hours until bedtime, or how many days until a special event!

Next Steps

  • Practice reading analog and digital clocks throughout the day
  • Try calculating elapsed time for your daily activities
  • Quiz family members on time conversions
  • Look for time problems in everyday situations