Price Change and New Price in Two Steps
Percentages are used very often in daily life. A shop might have a sale—for example, they’re offering a % discount)—or the price of a bus ticket might be increased by %.
Let’s begin by practicing how to find the new price without thinking about percentages:
Rule
Discount and Price Increase
New price = Old price - discount
New price = Old price + price increase
I will deal with discounts given as a percentage first.
Example 1
A jacket used to cost , but it is now being sold at a discount. What is the current price of the jacket?
You can figure out the answer in two steps:
The discount is
That helps give you the new price:
At other times, the price might be increasing by a given percentage. You find this new price in a similar way, you just have to add instead of subtracting.
Example 2
A monthly bus ticket used to cost , but then the price increased by . What is the new price?
You can do this in two steps the following way:
The increase in price is
The new price is:
