Minds On
Percents are all around us
Think of all the ways percent is represented everywhere. What purpose do they have? Reflect on the following images.
Brainstorm between 3 and 6 different ways percent has been represented in the world around you.
Action
Removing and adding percent amounts
Let's learn about how to add and subtract percents from the cost of an item. When determining the discount on an item, turn the discount percent into a decimal and multiply that by the cost of the item.
If the price of an item is $20 and the discount on that item is 12%, turn the percent into a decimal (.12) and multiply it by the original cost of the item.
20 × .12 = 2.40
Now we subtract $2.40 from the original $20.00 which gives us the new price of $17.60.
If we are adding tax of 12% to an item, the first part of the calculation is identical. The change is, instead of subtracting the $2.40 from the original price, we will now add that to the original price.
The new winter coat
The neighbourhood crossing guard needs a new winter coat and notices a clothing store in the mall is having a 25% off sale.
The coat is regular priced $60. What is the sale price? How many ways can you figure out how much is taken off?
When the crossing guard goes to pay at the cash register, the discount is taken off but 10% tax is added on. How much is added onto the sale price? What is the total amount he must give the salesclerk? How many ways can you figure out how much is added on?
Generate a list of real-life examples when percent is added or subtracted from totals.
Consolidation
Demonstrate your understanding
Complete one of the following two tasks to demonstrate your understanding of removing or adding percent.
- If you had to teach this concept to a student in your class who was absent for this lesson, how would you teach them? What would you say? Write a script or record a pretend conversation about this learning.
- Create a new scenario that involves adding or subtracting percent from a number. Be sure to solve the scenario as well.
Reflection
As you read the following descriptions, select the one that best describes your current understanding of the learning in this activity. Press the corresponding button once you have made your choice.
I feel...
Now, expand on your ideas by recording your thoughts using a voice recorder, speech-to-text, or writing tool.
When you review your notes on this learning activity later, reflect on whether you would select a different description based on your further review of the material in this learning activity.
Press ‘Discover More’ to extend your skills.
Discover MoreMall shopping
Analyn is shopping for clothes for school. Her favourite store is having a sale where items are “up to 30% off.” Her budget is approximately $300 after discount and taxes. Taxes are 13%. What items could Analyn buy? Record and calculate what her shopping receipt will show. Multiple items can be purchased. What does up to 25% off mean? Have you seen this wording before? Do you think it encourages people to buy more? Explain.
She also decides to pay using her credit card. The simple interest rate is 9% annually. If she decides to pay for the clothes over time using credit card instalments and it takes a year to pay her card off, how much more would she pay for the clothes? Explain what you have learned about credit card charges
Connect with a TVO Mathify tutor
Think of TVO Mathify as your own personalized math coach, here to support your learning at home. Press ‘TVO Mathify’ to connect with an Ontario Certified Teacher math tutor of your choice. You will need a TVO Mathify login to access this resource.
TVO Mathify (Opens in new window)