Opposite number facts for kids
An opposite number is a special number that helps us understand how numbers work together. Imagine you have a number, like 5. Its opposite number is -5. When you add 5 and -5 together, you always get zero! This idea is super important in mathematics.
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What is an Opposite Number?
In mathematics, an opposite number (also called an additive inverse) is a number that, when you add it to another number, gives you zero. Zero is a special number in addition because adding it to any number doesn't change that number. We call zero the identity element of addition.
For example, if you have the number 7, its opposite number is -7. Why? Because when you add them together, you get zero: 7 + (-7) = 0
We write the opposite number for any number n as −n. So, the opposite of 7 is written as −7.
Positive and Negative Numbers
The idea of opposite numbers is easy to see with positive and negative numbers.
For Positive Numbers
If you have a positive number, its opposite number is simply the negative version of that number.
- The opposite of 10 is -10. (Because 10 + (-10) = 0)
- The opposite of 25 is -25. (Because 25 + (-25) = 0)
For Negative Numbers
If you have a negative number, its opposite number is the positive version of that number.
- The opposite of -3 is 3. (Because -3 + 3 = 0)
- The opposite of -100 is 100. (Because -100 + 100 = 0)
What about Zero?
The number 0 is special! Its opposite number is 0 itself. Why? Because 0 + 0 = 0.
Why Are Opposite Numbers Important?
Opposite numbers are used all the time in math. They help us:
- Understand how numbers relate to each other on a number line.
- Solve equations where we need to "undo" an addition.
- Learn about more complex math ideas like inverse operations.
Related pages
See also
In Spanish: Opuesto para niños
