2. Percentage change
If a quantity goes through a change (increase or a decrease), we can work out the % change
E.g. I bought a second hand Toyota Corolla liftback for $ years later I sold it for $ Did I make a loss or a profit?
What was the percentage loss?

3. Cost Price, Selling Price, Profit and Loss.
E.g. Rhonda bought a parachute for $90. She sold it for $320. What was her profit? Express this profit as a % of the cost.
320 – 90 = $230 = Profit
%Profit = = 256%
E.g. Dino’s Dogfood Co. bought a bulk amount of dog biscuits for $885. They repackaged the biscuits, resulting in 60 packets in total and sold them for $13.50 a packet. Did they make a profit or a loss? Express this as a % of the cost price.

4. $13.50 × 60 = $810 = SP
SP – CP = 810 – 885 = - $75 which means a loss of $75
They experienced a 8.5% loss.