Science, Maths & Technology

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Everyday maths 1

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# 1.2 Negative numbers

So far you have only looked at positive numbers, but negative numbers are just as important. Negative numbers have a minus sign (–) in front of them.

Some examples of where negative numbers will apply to real life is with temperatures and bank balances, although hopefully our bank balances will not display too many negatives!

Perhaps you’ve seen negative numbers in weather reports where a temperature is below freezing, for example –2°C, or you may have seen them on frozen food packets.

If you ever have an overdraft at the bank, you may see minus signs next to the figures. If a bank statement reads –£30, for example, this tells you how much you’re overdrawn. In other words, what you owe the bank!

Where have you seen negative numbers recently? Look at this thermometer:

Figure _unit2.1.2 Figure 2 Negative numbers on a thermometer

It shows us that:

• –10°C is a lower temperature than –5°C
• –15°C is a lower temperature than –10°C.

## Box _unit2.1.1

Hint: ‘Lower’ means ‘less than’.

The lower the temperature, the colder it is.

## Activity _unit2.1.2 Activity 2: Using negative numbers in everyday life

1. The following table shows the temperatures in several cities on one day.
Table _unit2.1.3
City Temperature
A –2°C
B –5°C
C –1°C
D –8°C
E –3°C
• Which are the coldest and warmest cities?
1. A particular brand of ice cream includes the following note in its storing instructions:

• For best results, store in temperatures between –10°C and –6°C

If your freezer’s temperature was –11°C, would it be OK to keep this ice cream in it?