This is known as the commutative property of addition (and multiplication).
An easy way to remember the property is that the two elements commute, or exchange places, or that one element commutes from one side of the operation to the other, like a commuter (passenger) on a commuter train.
If you were to add 1+8+3 you'd get an answer of 12. The Commutative Property basically states that you can put these 3 numbers in any order and they'd be the same. EX: 8+1+3=12; 3+1+8=12;