# Elapsed Time Examples

lapsed time is simply the amount of time that passes from the beginning of an event to its end. In this lesson, you will learn how to solve for elapsed time and explore how it can be used in your everyday life.Defining Elapsed TimeSay it is currently 3:35pm in the afternoon and you are supposed to meet your best friend for dinner at 6:20pm.

## Calculating Elapsed Time

Before you leave your house you have to clean your room, shower, get dressed, and still have time to get to your friend’s house. Do you just wing it and hope you make it there on time?

- Or do you use your awesome math skills to figure out how much time you have to finish all of your tasks and arrive for dinner at 6:20pm?
- Elapsed time is the amount of time that passes from the start of an event to its finish.
- In simplest terms, elapsed time is how much time goes by from one time (say 3:35pm) to another (6:20pm). An important tool that goes hand and hand with elapsed time is the clock.
- Here are a few things we need to remember before we move on to calculating elapsed time.
- ClockThe hour hand on the clock is the shorter hand.The minute hand on the clock is the longer hand.We read time by looking at the hour hand first and then counting the minute hand.Each number on the clock equals five minutes.Now, there can be some difficulty when you try to just count in your head to figure out how much time has gone by, or elapsed.
- Instead of just jumping straight into using mental math (something that can increase our possibility for errors), we are going to learn about a really cool and easy way that we can organize our reasoning and make us experts in no time at solving for elapsed time.
- Elapsed Time Number LineLet’s look back at the example. We know that it is currently 3:35pm, and we have to be at dinner at 6:20pm.
- This means our start time is 3:35pm and our end time is 6:20pm. The first thing you always do when solving for elapsed time is to figure out your start time and end time.
- Once you have your important times, your next step is to draw a number line with these times. Number LineNow, people might differ on how they use their number line, but in our case, we are going follow a procedure that I think is the easiest to visualize.
- First, we are going to count to the nearest hour after our start time of 3:35pm. Looking at a clock, we know that the next hour to pass would be 4:00pm.
- So counting from 3:35 to 4:00 we see that there are 25 minutes between the two times. We are going to label this on our number line.
- Number line from 3:35pm to 4pmOur next step is to figure out the nearest hour before our end time. Looking at a clock, we know that the closest hour before 6:20pm would be 6:00pm.
- So, counting from 6:00pm to 6:20pm, we see that there are 20 minutes between the two times.
- We are going to label this on our number line. Number line from 6pm to 6:20pm.
- Time can be defined as the dimension based on which the evolution of any system takes place.
- We measure time in seconds, minutes, hours, days, weeks, months and years with clocks and calendars. Let us learn about these one by one. Time is measured in hours, minutes and seconds.
- How are these three related to each other? 1 minute = 60 seconds. 1 hour = 60 minutes. This means that 1 hour = 60 x 60 = 3600 seconds.
- A second is a very short period of time, say the time that is taken to blink your eye, to snap your fingers etc. it is a smaller unit of time than a minute. To understand how to tell time to exact minute, let us consider an example.
- Suppose Victor and his sister Alice were going to school. When they started from home, the following time was shown by the clock – .
- Victor asked her to read the time. She read it easily as 7:30. Then they reached the school and the time shown by the clock in the school is . Victor again asked her to read the time.

## Elapsed Time Meaning

But, she was not able to read the time to the exact minutes. Now, Victor told her it was 8: 10.

### Recommended Worksheets

Let us understand how to read time to exact minutes. If you see carefully, there are 12 numbers and 60 divisions on the face of a clock. Therefore, we have,. 1 hour = 60 minutes.

### Understanding Time

Hence, the number of divisions between two consecutive numbers is 60 ÷ 12 = 5 divisions or 5 minutes. We will read the time on the given clock as 2 :07 if,. The hour hand of the clock is at 2. The minute hand of the clock is at the 2nd division after the 1st number, i.e 7 minutes ( 1 x 5 = 5) + 2 minutes = 7 minutes. Hence, we can say that the numbers on the clock actually represent hours and the divisions between them represent the minutes.

### Telling Elapsed Time to Exact Minute

It is important to know here that – . Quarter of an hour = 60 ÷ 4 = 15 minutes. Half of an hour = 60 ÷ 2 = 30 minutes. 12 :00 o’clock in the night is 12:00 midnight. 12 :00 o’clock at the daytime is 12:00 noon. We do not write a.m. with 12:00 o’clock time. In what time to the hour, minute and second hands complete one round or one revolution of the clock? The hour hand of the clock goes round the clock in 12 hours.

## Visualising Elapsed Time on a Number Line

- The minute hand completes one round in 1 hour.
- The second’s hand completes one round in 1 minute.
- We can observe that there are 12 numbers written on the face of a clock.
- We also know that a day has 24 hours.
- Therefore, the hour hand of the clock completes 1 round in 12 hours.
- So, we divide 24 hours of a day in two periods:.
- From 12:00 midnight to 12:00 noon.
- From 12:00 noon to 12:00 midnight.
- The time between 12:00 midnight to 12:00 noon is written as a.m.
- means ante meridiem which means before midday.
- The time between 12:00 noon and 12:00 midnight is known as p.m.
- means post meridiem which means after midday.
- Another thing that should be noticed is that at times we see time written in a.m.
- while at times it is written as, say, 16:00 with no mention of a.m.
- There are two ways of telling the time:.
- The 12-hour clock runs from 1am to 12 noon and then from 1pm to 12 midnight.
- The 24-hour clock uses the numbers 00:00 to 23:59 (midnight is 00:00).
- Let us do a time comparison between the two styles of telling time.
- We see different types of clocks everywhere around us.
- But do we define a clock?