Measuring time is essential. To keep track of our daily activities and maintain our routine, we need to know the time duration for each one. Addition and subtraction are used to measure time.

**Addition of Time**

- Add the hours
- Add the minutes
- Add the seconds

Here the addition of time is discussed with example in two different processes.

**Example:**

- 4 hours 15 minutes 30 seconds + 6 hours 23 minutes 17 seconds
- 2: 27 + 4: 15

**Answer:**

a.

4hours 15 minute 30 second + 6 hours 23 minute 17 second = 10 hours 38 minute 47 second.

b.Add the hours: 2 + 4 = 6

Add the minutes: 27 + 15 = 42

So, the answer is 6:42..

**Subtraction of Time**

- Subtract the hours
- Subtract the minutes
- Subtract the seconds

Here the subtraction of time is discussed with example in two different processes.

**Example:**

- 8 hours 26 minutes 35 seconds – 4 hours 16 minutes 33 seconds
- 4: 37 pm – 2: 05 pm

**Answer:**

a.

8 hours 26 minutes 35 seconds – 4 hours 16 minutes 33 seconds

= 4 hours 10 minutes 2 seconds

b.Subtract hours: 4 – 2 = 2

Subtract minutes: 37 – 5 = 32

So, the answer is 2: 32.

**Subtraction is also used in finding the time duration or time interval of any activity.**

- Duration refers to the length of time that one event takes to be completed.
- Interval refers to the time between two events.

Here we discuss about duration and interval with real life example.

**Real-Life Problems**

**Example:**

- In Rithvik’s School, he gets a session on origami from 10:15 am to 11:30 am. What is the duration of the origami session?

**Answer:**

The duration of the origami session is 11:30 am to 10:15 am.

11 – 10 = 1

30 – 15 = 15

11: 30 – 10: 15 = 1: 15

Hence, the duration of the origami session is 1 hour 15 minutes.

2.Farhan’s flight took off at 3:33 pm. The exact time for the flight to take off was 2:25 pm. How late was the flight?

**Answer:**

The flight was late by 3:33 pm to 2:25 pm.

3 – 2 = 1

33 – 25 = 8

3:33 – 2:25 = 1:08

Hence, the flight was late by 1 hour 8 minutes.

Admissions Open for 2025-26