Rules and Properties

A = lw  (A is area, l is length, and w is width).

We usually use a raised dot, but not parentheses, for multiplication in order not to confuse readers with symbol x which is commonly used in Algebra

The number 2 is an example of a constant because it does not change value

Changing the order when adding does not affect the answer

a + b = b + a

Changing the grouping when adding does not affect the answer

(a + b) + c = a + (b + c)

When 0 is added to any number, the result is the same number

a + 0 = a                 or             0 + a = a 

Changing the order when multiplying does not affect the answer

             ba = ab

Changing the grouping when multiplying does not affect the answer

(ab)c = a(bc)

The product of 0 and any number is 0

0 ^. a = 0       and         a ^. 0 = 0

The product of 1 and any number is that number

1 . a = a               and               a . 1 = a

Any number divided by 1 is the number itself.  Any number (except 0) divided by itself is 1

a / 1 = a             and          a / a = 1        provided a ≠ 0