# 2.1: Mathematical Fundamentals


Changing the order of addends does not change their sum
$A+B=B+A \\ 3+2=5 \;\; while, \;\; 2+3=5$

note, subtraction is not commutative

$A-B \neq B-A \\ 3-2=1\;\; while, \;\; 2-3=-1$

## Commutative Property of Multiplication

$AB=BA$

Note division not commutative
$\frac{A}{B} \neq\frac{B}{A} \\ \frac{3}{2}=1.5,\;\;while\;\;\frac{2}{3}=0.67$