Adding and Subtracting Rules

When adding or subtracting numbers that have the same sign, you add the numbers together and keep the sign = = – 12 = – 16 = - 31

When adding or subtracting numbers that have opposite signs, you subtract the numbers and keep the sign of the larger number = 5 12 – 7 = = - 12 – = 7

Associative Laws The "Associative Laws" say that it doesn't matter how we group the numbers (i.e. which we calculate first)...when we add (a+ b) + c = a + (b + c)

Distributive Law The "Distributive Law" is the BEST one of all, but needs careful attention Try the calculations yourself: 3 × (2 + 4) = 3 × 6 = 18 3×2 + 3×4 = = 18 Either way gets the same answer

Commutative Laws The "Commutative Laws" say we can swap numbers over and still get the same answer... a + b = b + a

Inverse Operation The operation that reverses the effect of another operation. Example: Addition and subtraction are inverse operations Another Example: Multiplication and division are inverse operations.