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`.
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.