Home » Math Theory » Measurements and Time » Adding and Subtracting Time

## Definition

Time can be defined as a continuing and continuous chain of events that take place in order, from the past to the present to the future, in mathematics.

Duration is used to quantify, measure, compare, and sometimes even sequence the duration of events or the intervals between them.

Time tells us how long an activity or event will last. Hours, minutes, and seconds are the units of time that we use. There are 60 seconds in a minute and 60 minutes in an hour. A clock is a gadget that is used to keep track of time. When we look at the time on a clock, we can see when an event starts or ends. The clock, for instance, displays a time of 7 a.m.

#### Example

• Time between 6:34 am to 5: 55 pm
• 2:30 am to 5 :10 am

Each cycle (which consists of one day and one night) lasts 24 hours and is referred to as a day. Each hour (h) is divided into 60 minutes (min) and each minute into 60 seconds (s).

## Time Measurement Units

• A day is made up of 24 hours. For instance, we have 2 days how many hours in it?
• Then we know each day has 24 hours than 2 x 24 = 48 hours in two days.
• One hour is divided into 60 minutes. For example, Multiplying 2 by 60 takes 2 hours and 120 minutes.
• A minute is divided into 60 seconds.

Hence we can make a table as a summary

### Definition

The addition of time is comparable to the adding of integers, but in this case, we must consider the conversion. Time will be different from other mathematical conversion units since it is made up of 60 parts. One hour is divided into 60 minutes, while one minute is divided into 60 seconds. In addition, the presence of time creates a new barrier in terms of the format in which time is expressed. A 12-hour form or a 24-hour format is used to represent time.

The concept of time addition is essential in a variety of situations in our daily lives. For example, to determine the overall time spent by a student across various activities in a school, or to determine the total time spent by the student across various forms of transportation.

In arithmetic, adding time is the method of assigning and combining different time units such as hours, minutes, and seconds. In standard addition, a unit is divided into 1, 10, 100, and so on, whereas in time, a unit is divided into 60 subunits. Because of its uniqueness, adding time can be challenging at times. In adding, with the transformation of values greater than 60 into higher units, the combination of time can be done practically like a normal addition.

### Definition

If we know how to convert hours and minutes, adding time is a breeze. To begin, add all of the hours from the two times together. Add the minutes of the two times you’ve been provided. Put the time in hours: minutes format after that. Let’s take the time intervals of 9:10 and 1:15 as an illustration. The sum of hours 9 and 1 equals 10. The minutes 10 and 15 are added together to make 25. We obtain 10:25 by adding the calculated hours and minutes together. In rare circumstances, if the additional minutes are greater than 60, it is not possible to accept it immediately. Instead, we must deduct the additional minutes to change that to hours.

#### Example

Let’s have a look at another example. 7:45 and 3:25 are added together. 7 + 3 = 10, and 45 + 25 = 70 are the answers.

This 70 minutes cannot be consumed in one sitting. We know that one hour equals sixty minutes. The 70 minutes might be expressed as 60 minutes plus 10 minutes or 1 hour and 10 minutes. As a result, the time is 11:10 (11 hours and 10 minutes).Time Addition – 24 Hour Clock: In the United States, the 24-hour clock is commonly used and is referred to as personal time.

#### Example

An easy example is: What is the sum of 3:15 and 2:10?

Calculate the Hours: 2 + 3 Equals 5

Try to throw in the minutes: 15 plus 10 equals 25

Because the minutes are correct, the answer is 3:55.

Example 2

What is the sum of 3:55 and 5:20?

Calculate the Hours: 3 plus 5 equals 3

Toss in the minutes: 75 = 55 + 20

The minutes are at least 60, therefore

Put 1 to Hours (3+1 = 4 Hours) then subtract 60 from minutes (7560 = 15 Minutes).

4:15 is the solution.

### Time Addition – 12 Hour Clock:

The 24-hour clock is divided into two phases: a.m. (anti-meridiem) and p.m. (post-meridiem) (post-meridiem). The start of the day is considered midnight 12 a.m. on a 12-hour clock. In a 12-hour clock, the same adding process is used. Let’s look at subtracting period now.

#### Example:-

For instance, sum 4 hours 21 minutes by 2 h 47 mins.

Make sense all of the hrs. 4 hours plus 2 hours equals 6 hours

Add up all of the minutes. (Total time: 68 minutes) (21 minutes + 47 minutes)

If we already have 60 minutes or more, perform the following:

Subtract 60 minutes from the total time. (68 minutes divided by 60 minutes equals 8 minutes)

By just one, boost the amount of hrs. (7 hours) =(6 hrs + 1 hr)

If indeed the number of minutes is still 60 or more, continue the cycle.

7 hrs and mins is the solution.

Assume we want to know how long it will take to accomplish two jobs in hours and minutes. The first assignment will take 6 hours and 45 minutes, and the second task will take 9 hours and 30 minutes, according to your estimates.

You may also use the AutoSum method to sum integers and add up times. Choose AutoSum from the Home tab after selecting cell B4. The formula will be as follows: =SUM (A2:A3). To get the same outcome, press Enter for 16 hours and 15 minutes.

#### Example

In cell A2, write 6:45, and in cell A3, write 9:30.

Enter =A2+A3 in cell A4 and then hit Enter.

5 hours 25 minutes plus 2 hours 47 minutes equals 5 hours 25 minutes plus 2 hours 47 minutes.

Stack up all of the hours. (5 hours plus 2 hours Equals 7)

Add up all of the minutes. (25 minutes plus 47 minutes equals 72 minutes)

If you have 60 minutes or more, perform the following:

Subtract 60 minutes from the total time. (72 minutes divided by 60 minutes equals 12 minutes)

By one, increase the amount of hours. 7 hours plus 1 hour equals 8 hours

If indeed the number of minutes is still 60 or more, continue the cycle.

8 hours and 12 minutes is the answer.

## Taking away the hours and minutes

### Method to subtract the hours

The methods to remove time (5 hours 45 minutes – 3 hours 20 minutes) in hours and minutes are listed below.

• Step I: Determine whether the first time’s minutes (5 hours 45 minutes) are less than the second time’s minutes (3 hour 20 minutes). So, if that’s the case,

Take one away from the first time’s hours.

Add 60 minutes to the time you spent the first time.

(Because 45 is greater than 20, we proceed to the following stage.)

• Step 2: Subtract the minutes from the total. (20 minutes minus 45 minutes) Equals 25 minutes

Minus the hours in step three. 4 hours minus 2 hours equals 2 hours

As a result, the solution is the sum of the results of Steps II and III (2hours 25minutes).

## How Do We Subtract Hours and Minutes in Hours and Minutes?

The steps for subtracting time are as follows.

1. We must first subtract hours.

2. Deduct the minutes from the total.

3. If indeed the minutes are less than the minimum, add 60 to the minutes before subtracting the values.

Note:-

Add 12 hours and use am from 0:00 to 0:59. Simply add am after the time from 1:00 to 11:59. Simply add PM after the time between 12:00 and 12:59. Subtract 12 hours from 13:00 to 0:00 and use PM.

Hence, Time Subtraction

The process of subtracting time is nearly identical to the process of adding time. We do it by following a few basic steps. Subtract the hours first, followed by the minutes. Also, write the hours and minutes as a result of the calculation. Let’s have a look at a simple example. Let’s take 5:45 out of 7:55. Let’s start by subtracting the hours 7 – 5 = 2, and then the minutes 55 – 45 = 10. The final result can be written as 2:10.

#### Example

Consider subtracting 6:45 a.m. from 12:10 p.m. in another example. 45 minutes is more than 10 minutes, as we can see. So, to continue subtracting, we’ll take minutes from 12 hours and give them to 10 minutes. We have 12 hours if we take 60 minutes from 1 hour. 11 hours, 60 minutes Plus 10 minutes, or 11 hours and 70 minutes, is equivalent to 10 minutes. We now have a total of 70 minutes, which is longer than 45 minutes. As a result, we’ll do the decrease.

Between 6:45 a.m. to 12:10 p.m., we have 5 hours and 25 minutes. So now we know how to add and subtract time.

### Let’s have a look at some time management tips and strategies.

To compute the overall time, add all the hours and minutes together. Subtract all of the hours and minutes to get at the time.

If the total number of minutes exceeds 60, subtract 60 and consider the remaining minutes to be the total. The 60 minutes deleted are converted to an hour and then added to the hours.

If the minutes are negative while subtracting them, add 60 minutes to all of them and count the result as minutes. Those extra 60 minutes, which are counted as an hour, are deducted from the overall number of hours.

### Subtracting Time from the Clock

To remove two clock timings (4:45 pm – 2:20 pm), follow these steps:

#### Case I: If both times are in the morning or evening

Step I: Determine whether the minutes of the first time (2:45 p.m.) are less than those of the second time (2:45 p.m.) (2:20 pm). So, if that’s the case,

Take one away from the first time’s hours.

Add 60 minutes to the time you spent the first time.

(Because 45 is greater than 20, we proceed to the following stage.)

Step 2: Subtract the minutes from the total. (45 minutes minus 20 minutes = 25 minutes)

Subtract the hours in step three. 2 hours (4 – 2)

As a result, the solution is the sum of the results of Steps II and III (2 hours 25 minutes).

Exercising your problem-solving skills in Example 2

A: 8:15 p.m. to 6:45 p.m.

Solution:

A. 8:15 p.m. – 6:45 p.m.

#### Case ii

Step I: Because 15 is less than 45, we subtract one hour from the first time’s hours and add 60 minutes to the first time’s minutes.

8 minus 1 equal 7 hours

15 minutes plus 60 minutes equals 75 minutes.

Step 2: When we subtract the minutes, we obtain

30 minutes, 75 minutes, 45 minutes, 75 minutes, 45 minutes, 75 minutes, 45 minutes, 75 minutes

Step 3: After subtracting the hours, we arrive at

Seven – six

a single hour

As a result, the correct answer is 1 hour and 30 minutes.

#### Example

6 hour 5 minutes – 4 hours 45 minutes

Hour          minutes

### Determining the Change in Hours, Minutes, & Seconds between Two Times

Calculate the time difference among 6 hours, 48 minutes, 27 seconds and 3 hours, 33 minutes, 13 seconds.

We use a time line to determine the difference between two given times.

We start by placing the following minute after the previous time, which is 3 hours and 34 minutes, and next hour, which is 4 hours.

In a second phase, we place the previous hour before the later time: 6 hours and 48 minutes, and the last minute before the later time: 6 hours and 48 minutes.

The numbers of seconds between 3 hours, 33 minutes, and 13 seconds and 3 hours, 34 minutes, which would be the number of seconds added to 13 to reach 60, is then calculated.

This is 47 seconds, according to our calculations. Then there’s a 26-minute gap among three hours and 34 minutes and four hours.

The time difference between 4 and 6 hrs is 2 hours, the time difference between 6 and 6 hours and 48 minutes is 48 minutes, as well as the time difference between 6 and 48 minutes and 6 hours,48 mins, and 27 seconds is 47 secs.

So there’s a 3 hour, 15 minute, and 14 second discrepancy between the two timings.

## Subtracting hours in excel

### Definition

Simply subtract time in Excel is simple, but maintaining the appropriate structure is a little more difficult. Select the cell with the most recent time and remove it from the older time lap to subtract the time. In Excel, there is no unique function for subtracting time; instead, it is a collection of multiple operations. It tells us the precise time difference.

Let’s imagine we want to figure out how many hours an employee worked based on her timecard’s clock-in/clock-out times. She is scheduled to arrive at 9:15:00 a.m. and depart at 4:50:15 p.m. We’re utilizing seconds here, but you can adjust if we just want.

#### Example

In cell B1, type 9:15:00 AM, and in cell B2, type 4:50:15 PM.

To remove time, type =B2-B1, and the elapsed time will be returned. To alter the time format, right-click on the answer and select Format Cells, then change it to it. It’ll give you a time-formatted response (7:35, or 7 hours and 35 minutes).

To deduct time that is longer than 24 hours, use the following formula:

To deduct the difference between two times that total more than 24 hours, a formula must be created.

Follow the below steps below to get started:

Choose cell B1 and drag to cell B2 to implement the formatting towards both cells at the same time, as seen in the example above.

Inside the Using the box, in the Drop down list, selects Customized.

Enter m/d/yyyy h: mm AM/PM in the Format box at the top of the list of formats.

Take note of the empty spaces at the end of yyyy and mm.

This new layout will be available in the Type list whenever you need it.

## Conclusion

A time line is handy for subtracting times. We begin by placing the time we need to subtract from the other time, and then we look for the time we need to add to this time in order to get the other one, adding seconds first to reach the next full minute, then minutes to the next full hour, then hours to the next full day (if necessary), then adding the number of days, then hours, then minutes, and finally seconds to get the other one. The difference between the second and first times is the sum of all the times added to the first time.