Why do we use percentages

Home: Purpose of Website. About me. Math Standards: Importance of Percentages. Virtual Math Manipulatives: Websites as Resources. Knowing about percentages is important because we use this in our daily lives. We'll move the decimal point two places to the left Now we can multiply: 0. Remember, sales tax is an extra charge added to the price of an item. So we'll add the sales tax to our original price. Let's try another example.

Now we'll multiply: 4. Find the total cost of each item after sales tax. Be sure to round your answer to the nearest cent. Have you ever bought something on sale marked down by twenty percent? If so, you've used a discount. A discount is usually a percentage of the original price. The percentage is subtracted from the original price to determine the sale price.

How much would the shirt cost after the discount? This means it will cost fifty percent less than the original price, or half as much. This discount is a percentage of the original price. Two bakeries called Browie and Best Bake both bake bread. On a particular day, 27 out of 40 loaves in Browie Bakery were baked on the previous day. At the Best Bake Bakery 57 out of 90 loaves were baked the previous day. Which bakery was selling the larger percentage of loaves baked the previous day?

The percentage of loaves baked on the previous day for the Best Bake Bakery is:. A student scores in one test and in a second test. Express each score as a percentage and hence state the better score. What was the population at the beginning of the week?

Find the amount of money. How much did Julie invest? Sums and differences of percentages. Percentages can sometimes be added and subtracted.

In practical applications it is important that you are adding or subtracting percentages of the same quantity. The other people on the platform are not reading. What is the percentage of people both reading and wearing sun glasses?

Eighty percent of people in a bus are reading a newspaper. Fifteen percent are reading a novel. A person cannot be reading both. The percentage of students in the class who are boys with blue eyes is given by. There are 65 spectators in a football stadium. Sixty percent of a group of people work full time. Fifteen percent of those who work full time are married.

What is the percentage of people of the group who are married and work full time. Percentage increase and decrease.