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Here we will learn about converting units of time, including converting between seconds, minutes and hours.

There are also worksheets based on Edexcel, AQA and OCR exam questions, along with further guidance on where to go next if you’re still stuck.

**Converting units of time** is converting between seconds, minutes and hours.

To do this we need to know how different units of time are related to each other:

1 day = 24 hours

1 hour = 60 minutes

1 minute = 60 seconds

E.g

Convert 4 hours to minutes.

4 \times 60=2404 hours = 240 minutes

In order to convert units of time:

**Check the units involved.****Multiply or divide by the conversion factor.****Write the answer**.

Get your free converting units of time worksheet of 20+ questions and answers. Includes reasoning and applied questions.

COMING SOONGet your free converting units of time worksheet of 20+ questions and answers. Includes reasoning and applied questions.

COMING SOON**Converting units of time** is part of our series of lessons to support revision on **units of measurement**. You may find it helpful to start with the main units of measurement lesson for a summary of what to expect, or use the step by step guides below for further detail on individual topics. Other lessons in this series include:

How many hours are there in 1.5 days?

**Check the units involved.**

1 day = 24 hours

So the conversion factor is 24.

2**Multiply or divide by the conversion factor.**

We need to multiply by 24.

1.5 \times 24=363**Write the answer.**

1.5 days is 36** **hours

How many minutes are there in 2.3 hours?

**Check the units involved.**

1 hour = 60 minutes.

So the conversion factor is 60.

**Multiply or divide by the conversion factor.**

We need to multiply by 60.

2.3 \times 60=138

**Write the answer.**

2.3 hours is 138 ** **minutes

Convert 1.4 hours to hours and minutes.

**Check the units involved.**

1 hour = 60 minutes.

So the conversion factor is 60.

**Multiply or divide by the conversion factor.**

We need to concentrate on the decimal part of the original number, 0.4.

We multiply by 60 to convert to minutes

0.4 \times 60= 24

**Write the answer.**

1.4 hours is 1 hour 24 minutes

Convert 324 minutes to hours.

**Check the units involved.**

1 hour = 60 minutes.

So the conversion factor is 60.

**Multiply or divide by the conversion factor.**

We need to divide by 60.

324 \div 60=5.4

**Write the answer.**

324 minutes is 5.4 ** **hours

Convert 520 minutes to hours and minutes

**Check the units involved.**

1 minute = 60 seconds

So the conversion factor is 60.

**Multiply or divide by the conversion factor.**

We need to divide by 60.

520 \div 60= 8.66666..... = 8\frac{2}{3}

There are 8 full hours and \frac{2}{3} of an hour.

Let’s convert \frac{2}{3} of an hour to minutes by multiplying by 60.

0.66666… \times 60 =\frac{2}{3}\times 60 = 40

**Write the answer.**

520 minutes is 8 ** **hours and** ** 40 ** **minutes

Convert 2 hours and 45 minutes to hours.

**Check the units involved.**

1 hour = 60 minutes.

The conversion factor is 60.

**Multiply or divide by the conversion factor.**

We need to concentrate on the minutes part and convert it to hours by dividing by 60.

45\div 60=\frac{45}{60}=0.75

**Write the answer.**

2 hours and 45 minutes is 2.75 ** **hours

\bf{10}**Base**\bf{60}**and base**

A common misconception is to confuse the units used in the metric system with the units used for time.

The **metric system** uses base 10 .

Each successive unit is 10 times larger than the previous one.

E.g.

**Time **uses base 60.

E.g.

1. How many hours are there in 2\frac{1}{2} days?

60 hours

48 hours

72 hours

63 hours

2\frac{1}{2}\times 24=60

2. How many minutes are there in 3.1 hours?

31 minutes

190 minutes

186 minutes

310 minutes

3.1\times 60=186

3. Convert 4.35 hours to hours and minutes?

4 hours and 35 minutes

4 hours and 25 minutes

4 hours and 21 minutes

4 hours and 28 minutes

Concentrate on the decimal fraction part

0.35\times 60=21

So, 4.35 hours is 4 hours and 21 minutes.

4. Convert 75 minutes to hours?

0.75 hours

1.5 hours minutes

7.5 hours

1.25 hours

75\div 60=1.25

5. Convert 135 minutes to hours and minutes?

13 hours and 5 minutes

1 hours and 35 minutes

2 hours and 25 minutes

2 hours and 15 minutes

135\div 60=2.25

So there are 2 hours.

0.25\times 60=15

And there are 15 minutes

6. Convert 4 hours and 18 minutes to hours?

4.3 hours

4.18 hours

4.2 hours

4.81 hours

First look at the minutes

18 \div 60=0.3

So the minutes are 0.3 hours.

Altogether there are 4.3 hours.

1. How many days are 120 hours?

A B C D

12 \quad \quad \quad 10 \quad \quad \quad 5 \quad \quad \quad 2

Circle the correct answer.

**(1 mark)**

Show answer

120\div 24=5

C – 5 hours

**(1)**

2. (a) Write 102 minutes as hours

(b) Write 2 hours and 48 minutes as hours.

**(4 marks)**

Show answer

(a)

102\div 60

**(1)**

1.7 hours

**(1)**

(b)

48\div 60=0.8

**(1)**

2.8 hours

**(1)**

3. Work out how many seconds there are in 3 hours.

**(2 marks)**

Show answer

3\times 60 \times 60

**(1)**

10 \ 800 seconds

**(1)**

You have now learned how to:

- Change between standard units of time

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#### GCSE Maths Papers - November 2022 Topics

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