# Commutative Property of Addition

**Commutative property of addition**:

` huge color(purple)(a+b=b+a) `

What does it mean?

It means, that order of numbers doesn't matter.

Indeed, suppose your first friend (let's call it Tom) gave you 3 apples, then your another friend (let's call it Jim) gave your 4 apples. You got total of 7 apples.

But does really matter, who gave the apples first? If Jim gave you 4 apples and then Tom gave you 3 apples, you got also 7 apples.

**Warning**: it doesn't work with subtraction, i.e. `a-b!=b-a`.

For example, `4-3!=3-4`.

However, commutative property of addition works for negative numbers (in fact, for real numbers) as well.

**Example 1**. `3+(-4)=(-4)+3`.

**Example 2**. `(-2.51)+(-3.4)=(-3.4)+(-2.51)`.

**Example 3**. `5/8-2/3=5/8+(-2/3)=(-2/3)+5/8`.

**Conclusion**. So, the basic rule here is following: whenever you see addition, you can interchange addends.