Integers: numbers below 0

Negative numbers on the number line: compare, add and subtract. Read one step, play with it, then tap “I understand this”.

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Numbers below 0

When it is very cold, the temperature drops below 0 °C: −3 °C is three degrees below freezing. Numbers below 0 are negative numbers.

Play · Change the numbers

Change the temperature.

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On the number line a number further left is always smaller. That is why −8 < −2, even though 8 looks bigger than 2.

Watch out

−10 is smaller than −1. Think of debt: owing R10 leaves you with less than owing R1.

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Adding a positive number: jump right. Adding a negative number: jump left. 3 + (−7) = −4.

Play · Change the numbers

Choose add or subtract and change the numbers.

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Subtracting a negative is the same as adding: 5 − (−3) = 5 + 3 = 8. The two minuses become a plus.

Rule

− (−) becomes + . Think: if someone takes a debt away from you, you are richer.

Why does minus-minus become plus?

Look at the pattern: 5 − 2 = 3, 5 − 1 = 4, 5 − 0 = 5. Every time you subtract 1 less, the answer gets 1 bigger. The pattern carries on: 5 − (−1) = 6.

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Game

Choose the right answer.

Correct: 0

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Remember this: your summary

Write these points in your maths book. Read them again the night before the test.

Quiz

Tap an answer. If you get one wrong, read why and go back to that step. You get new questions every time.

You ticked all 5 steps! Now you are ready for the quiz.

Free PDF to downloadPrint the practice sheet and practise on paper. The memo is on page 2: try on your own first.

Ready for more? The Grade 7 integers quiz gives you new sums every time.

For parents

One step a day is enough. Ten calm minutes work better than an hour the night before the test.
Use the weather forecast: “This morning it was −2 °C and this afternoon 14 °C. How many degrees warmer did it get?”
Ask your child to tell you the rule in their own words. If they can explain it, they understand it.
The ticks (“I understand this”) are saved on this device only. We never ask for names or emails.

Follows CAPS for Grade 7 Maths. Always check your teacher’s notes and textbook too.