Addition and Subtraction of Time

Addition and subtraction of time help us calculate the total time or find the difference between two times. We use these skills in daily life to find how long an activity takes, when it ends, or how much time has passed between two events.

In this lesson, students will learn how to add and subtract hours, minutes, and seconds. They will also learn to find elapsed time between a start time and an end time. The concepts are explained using examples and practice questions to help students understand and apply them easily.

Quick Answer: Addition and subtraction of time help us calculate the total time or find the difference between two times.

Operation	Meaning	Example
Addition of Time	Add two or more time values together	2 h 30 min + 1 h 20 min = 3 h 50 min
Subtraction of Time	Find the difference between two times	5 h 20 min − 2 h 10 min = 3 h 10 min
Elapsed Time	Time passed between a start time and an end time	1:00 PM to 3:00 PM = 2 hours

Download the elapsed time worksheet and check the solutions to the elapsed time question for class 5 provided in PDF format.

Addition and Subtraction of Time:

Time Addition:

The Steps to Add Times Are the Following:

Elapsed time basically shows the time difference. Here students will learn about elapsed time.

• Arrange the times in the column according to the hours, minutes, and seconds.
• Add the seconds. If the seconds are more than 60 then subtract 60 from it and add 1 to the minute.
• Add the minutes. If the minutes are more than 60 then subtract 60 from it and add 1 to the hour.
• Add the hours.

Example:

Add 5 h 20 minutes 54 seconds and 2 hours 12 minutes 12 seconds.

Solution:

Step 1: Arrange both the times column-wise.

Step 2: Add 54 seconds and 12 seconds. The sum is 66 seconds which is more than 60.

Step 3: Subtract 60 from the sum 66. Write the difference 6 in the second column and add 1 to the minute’s column.

Step 4: Add 20 minutes, 12 minutes, and 1 minute. Write the sum 33 in the minute’s column.

Step 5: Add 5 hours and 2 hours. Write the sum 7 hours in the hour’s column.

• Sometimes hour may also end up to large.
• If the hour is more than 24 then subtract 24 from it and add 1 day.
  
  

Time Subtraction:

The Steps to Subtract Times Are the Following:

• Arrange the time in the column according to the hours, minutes, and seconds.
• Subtract the seconds. If the second’s value in the minuend is smaller than the value in the subtrahend then borrows 1 minute (60 seconds) from the minute’s column.
• Subtract the minutes. If the minute’s value in the minuend is smaller than the value in the subtrahend then borrows 1 hour (60 minutes) from the hour’s column.
• Subtract the hours.

Example:

Subtract 3 h 12 minutes 48 seconds from 5 hours 20 minutes 12 seconds.

Solution:

Step 1: Subtract 48 seconds from 12 seconds. Since 48 > 12. Borrow 1 minute (60 seconds) from the minute’s column.

Step 2: Now subtract 48 from (60 + 12) = 72 seconds. Write the difference in 24 seconds in the second column.

Step 3: Subtract 12 minutes from 19 minutes. Write the difference 7 minutes in the minute’s column.

Step 4: Subtract 3 hours from 5 hours. Write the difference of 2 hours in the hour’s column.

What Is Elapsed Time?

Elapsed time is defined as the total time that has passed from the starting time to the ending time.

Steps to find the elapsed time:

• Note the start time.
• Note the end time.
• Subtract the start time from the end time.

Example:

Write the time elapsed for the given pair of clocks:

Solution:

The time on the first clock is 1: 10

The time on the second clock is 8:20

Time elapsed is equal to the difference between 8 hours 20 minutes and 1 hour 10 min.

Common Addition and Subtraction of Time Examples

The table below shows common examples of addition, subtraction, and elapsed time calculations.

Question	Answer
2 h 30 min + 1 h 20 min	3 h 50 min
4 h 45 min + 2 h 30 min	7 h 15 min
5 h 20 min − 2 h 10 min	3 h 10 min
8 h 15 min − 3 h 45 min	4 h 30 min
9:00 AM to 12:30 PM	3 h 30 min
2:15 PM to 5:45 PM	3 h 30 min

Practice Questions on Addition and Subtraction of Time Questions

1. Add 2 h 35 min and 1 h 20 min.
2. Add 4 h 15 min and 3 h 50 min.
3. Subtract 2 h 20 min from 5 h 45 min.
4. Subtract 1 h 35 min from 4 h 10 min.
5. Find the elapsed time between 9:15 AM and 12:45 PM.
6. Find the elapsed time between 2:30 PM and 6:00 PM.

Answer Key:

1. 3 h 55 min
2. 8 h 5 min
3. 3 h 25 min
4. 2 h 35 min
5. 3 h 30 min
6. 3 h 30 min

Free Downloadable Addition and Subtraction of Time Worksheet

Download and print this worksheet to practice addition and subtraction of time using hours, minutes and seconds.

Addition and Subtraction of Time Worksheet

Frequently Asked Questions on Addition and Subtraction of Time

1. What is addition of time?

Answer: Addition of time means adding hours, minutes and seconds to find the total duration.

2. What is subtraction of time?

Answer: Subtraction of time means finding the difference between two time values.

3. How do you subtract time with hours and minutes?

Answer: Arrange the times in columns and subtract minutes first. If needed, borrow 1 hour as 60 minutes.

4. What is elapsed time?

Answer: Elapsed time is the amount of time that passes between a start time and an end time.