mrs. herbison’s 3 grade math lesson. the word percent means “per 100,” “out of every 100”...
TRANSCRIPT
LEARNING SIMPLE PERCENTAGES
Mrs. Herbison’s 3 Grade Math Lesson
What are Percentages?
Review
The word percent means “per 100,” “out of every 100” or “for every 100” Meaning there are 30 houses out of every 100
house in this town is white.
How to calculateWhat is 30% of 20?
First, replace 30% with 30/100 Then, replace “of” with “times” Finally, carry out the multiplication of (30/100) times 20 to
get the answer of 6
In the Real World…
Where do we see percent's (%)?????
On sales flyers
On our phone’s battery life
Food packages
Clothing tags
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Real World Problems
Sally is planning a dinner party and needs new dinner wear. Sally has picked out a set of 4, White Nomad Elephant Plates that cost $20.00. The store is running a sale on all dinner wear of 20 % off the price. How much is the discount off the plates? Work it out…
20 % of $20.00 ?20/100 x 20 = 4
Sally will receive a discount of $4.00.
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Real World Problem
We figured out how much Sally’s discount would be now lets figure out the actually cost of the plates.
Sally is hosting a party of 4 people so only one set of dishes is needed. The original cost of the dishes is $20.00. The discount of 20% off equals to $4.00.
Work it out… $20.00 minus $4.00?
20-4 = 16
Sally will pay $16.00 for a set of 4 dishes.
Did you know…?
Sales tax is a percentage of the items you buy. In Arizona our sales tax is 9.73%. We will round this number to an even 10% to solve the next portion of our problem. Sally heads to the cashier with her dishes. Who promptly rings her order up. “Will that be all, Miss?”
What is Sally’s total including sales tax?
Work it out…We know that the original price of the dishes is $20.00 , less a discount of 25%($4.00) will be $16.00? The added sales tax is 10% of the sale
price10/100 x $16 is $1.60.
Next add the sales tax to the total$1.60 + $16.00 = $17.60
Sally will pay $17.60 for her new dinner ware.
Questions?
Does everyone understand how we got our answer?
Do you think Sally got a bargain for her dinnerware?
Why do you think we have to pay sales tax?
Try It Own Your Own…
Matthew goes to the store to buy a new laptop. The cost of the laptop is $350.00. In the sales paper for the store is a coupon for 50% off a purchase over $300.00. State sales tax is 10%. What is the total cost of Matthew’s new laptop?
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