An integer is a whole number with no fraction or decimal part, and it can be positive, negative or zero. So −7, 0 and 12 are integers, while −2.5 and 1/2 are not. Two of the three levels here make a pure integers game, from −20 + 17 to −9 × 12. The third adds one decimal place, as in −4.4 − (−6.1).

How do you add numbers with different signs?

To add a positive and a negative number, find the gap between their sizes, ignoring the signs, then give the answer the sign of the larger size. For −13 + 8, the sizes are 13 and 8, and the gap is 5. The negative part is larger, so −13 + 8 = −5. On a number line, 8 steps right from −13 also land on −5.

Why is a negative times a negative a positive?

A negative times a negative is positive because the times table pattern has to keep going past zero. Multiply by −3 and count the first number down: 2 × (−3) = −6, 1 × (−3) = −3 and 0 × (−3) = 0. Each answer is 3 more than the one before. Carry on, and −1 × (−3) = 3, then −2 × (−3) = 6.

Why does my child think −8 is bigger than −3?

Many children think −8 is bigger than −3 because 8 is more than 3, and above zero more always means bigger. Below zero the order flips. On the number line −8 sits further left, so it is the smaller number, written −8 < −3. A freezer at −8 °C is colder than one at −3 °C, which makes the idea easy to check.

Can I use this negative number game in class without paying?

Yes, every level is free for a class: pupils open it in a browser on laptops or tablets, with no sign-up or download. For five minutes of signed numbers practice, write 6 + 4, 6 + (−4), −6 + 4 and −6 + (−4) on the board. Pupils predict which answers fall below zero, then check: 10 and 2 stay above, −2 and −10 drop below. A teacher dashboard on the schools plan, priced per student, shows who is getting better with negatives.

Math practice · reimagined

Negative Numbers Game

Q: Can I use this negative number game in class without paying?

Yes, every level is free for a class: pupils open it in a browser on laptops or tablets, with no sign-up or download. For five minutes of signed numbers practice, write 6 + 4, 6 + (−4), −6 + 4 and −6 + (−4) on the board. Pupils predict which answers fall below zero, then check: 10 and 2 stay above, −2 and −10 drop below. A teacher dashboard on the schools plan, priced per student, shows who is getting better with negatives.

This negative numbers fighting game adds a − key to your keypad, for problems like −4 − (−6), decimals like −0.7 + (−0.8) and products as low as −144. Nail the number and its sign before your rival, and your fighter strikes first.

Ages 4–99+ · no download · plays in your browser · 23 languages

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What are negative numbers?

Negative numbers are numbers below zero, written with a minus sign in front, such as −5. On a number line they sit to the left of zero, and the further left a number lies, the smaller it is. A diver 6 metres under the sea is at −6 metres. Numbers written with their sign, + or −, are called signed numbers.

Every level of Signed numbers

Example: −9 − (−4), taking away a negative

Two minus signs stand side by side here, because you are taking away −4, a negative number.
Removing −4 does the same as adding 4, so the problem turns into −9 + 4.
Start at −9 on a number line and move 4 steps right, towards zero. You land on −5.
The answer is −5, so you type 5 and press the − key.

Learn it step by step

Picture a number line stretching left (negative) and right (positive) from zero. Adding moves you right, subtracting moves you left — and a negative number flips the direction.

So 5 + (−8) means start at 5 and move 8 to the LEFT, landing on −3. And 5 − (−2) is a double-flip: subtracting a negative actually moves you RIGHT, so it's the same as 5 + 2 = 7. Two minuses next to each other turn into a plus.

Take it one step at a time along the line, and type where you land — use the − key if you end up below zero.

Tips and common mistakes

Picture a negative number as a debt. Owing 8 coins and then earning 3 leaves you owing 5, so −8 + 3 = −5.
A common slip is adding the sizes and keeping the minus, so −6 + 2 turns into −8. Adding 2 moves you 2 steps right, towards zero, so −6 + 2 = −4.
Tape a number line from −10 to 10 along the floor. Call out a problem such as −3 + 5, and your child walks it from −3 to land on 2.

How to play

Problems such as 14 + (−18) or −6 × (−11) put negative numbers on screen, with brackets around any negative that follows a sign. Type the result on the keypad, pressing − for answers below zero, plus the decimal point on the decimals level, as in −1.5. Get it in before your rival and Pea Pod attacks, harder the faster you are.

— Quick answers —

Signed numbers: the short FAQ

What is an integer?: An integer is a whole number with no fraction or decimal part, and it can be positive, negative or zero. So −7, 0 and 12 are integers, while −2.5 and 1/2 are not. Two of the three levels here make a pure integers game, from −20 + 17 to −9 × 12. The third adds one decimal place, as in −4.4 − (−6.1).
How do you add numbers with different signs?: To add a positive and a negative number, find the gap between their sizes, ignoring the signs, then give the answer the sign of the larger size. For −13 + 8, the sizes are 13 and 8, and the gap is 5. The negative part is larger, so −13 + 8 = −5. On a number line, 8 steps right from −13 also land on −5.
Why is a negative times a negative a positive?: A negative times a negative is positive because the times table pattern has to keep going past zero. Multiply by −3 and count the first number down: 2 × (−3) = −6, 1 × (−3) = −3 and 0 × (−3) = 0. Each answer is 3 more than the one before. Carry on, and −1 × (−3) = 3, then −2 × (−3) = 6.
Why does my child think −8 is bigger than −3?: Many children think −8 is bigger than −3 because 8 is more than 3, and above zero more always means bigger. Below zero the order flips. On the number line −8 sits further left, so it is the smaller number, written −8 < −3. A freezer at −8 °C is colder than one at −3 °C, which makes the idea easy to check.
Can I use this negative number game in class without paying?: Yes, every level is free for a class: pupils open it in a browser on laptops or tablets, with no sign-up or download. For five minutes of signed numbers practice, write 6 + 4, 6 + (−4), −6 + 4 and −6 + (−4) on the board. Pupils predict which answers fall below zero, then check: 10 and 2 stay above, −2 and −10 drop below. A teacher dashboard on the schools plan, priced per student, shows who is getting better with negatives.

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