1. Ratios and Proportions Notes-Part 6

2. Reduce or Enlarge
When looking at pictures, sometimes they must be reduced or enlarged to fit a certain purpose. In the example below, the picture on the right is the original. The picture on the left needed to be resized in order to fit on a flyer.

3. Reduce or Enlarge
Is the change a reduction or an enlargement? By what percent?
What does it mean to reduce to 25% or enlarge to 400%?

4. Reduce or Enlarge
The printer has gone to a lot of trouble to find the effect of a reduction. It would be a lot easier if the print shop had a chart that shows the measurements of an object after it is reduced.

5. Reduce or Enlarge
How can a calculator be used to find a reduction of 30% Use arrow language to show the process.

6. Reduce or Enlarge
The city wants to make a poster using the original picture. This time the picture has to be enlarged. Find the dimensions of a picture 10 centimeters (cm) by 15 cm enlarged to 200%. Show your calculations.
Suppose you want to make an enlargement to 200%. The photocopier you are using enlarges to only 150%.
Will two enlargements to 150% give the desired result? Explain.
Find two enlargements that can be used with this photocopier to produce a final enlargement as close as possible to 200%. Copy the arrow string to describe your result.

7. Discounts
The city manager went to the Office Supply Store to buy a frame for the new subway poster. There were several frames for sale. He liked the picture shown below.
What is the discount in dollars?
The city manager calculated the discount with one multiplication:
0.25 x Is this correct? Explain.
What multiplication sentence could be used to calculate the sale price?

8. Sales Tax
The city manager paid more than $9.75 for the frame. When they looked at the bill, they noticed a sales tax added to their purchase. Sales taxes help pay for local community services. In many cities, the sales tax is 8%. So, for an item priced at $20, you would pay $20 plus 8% of 20.

9. Sales Tax
Strategy 1: Ratio Table Use the ratio table to calculate 8% sales tax on a $20 purchase

10. Sales Tax
Strategy 2: Percent Bar Use the Percent Bar to calculate 8% Sales Tax on a $20 purchase.

11. Sales Tax
Strategy 3: Arrow Language Use the Percent Bar to calculate 8% Sales Tax on a $20 purchase.

12. Sales Tax What fraction corresponds to 8%?
What decimal corresponds to 8%?
How could you use multiplication to find the total cost of a bill with 8% sales tax?

13. Sales Tax
Fill in the table below. Use a sales tax of 19%

14. Sales Tax
The city manager stopped for groceries on his way home. He bought the following items. The sales tax is 8%. What was the total cost of his trip to the grocery store?