1 / 17

Proportions

Proportions. What are proportions?. An equation in which two ratios are equal is called a proportion A proportion can be written using colon notation like this a : b :: c : d or as the more recognizable (and useable) equivalence of two fractions. _ a __ = _ c __ b d.

robertccox
Télécharger la présentation

Proportions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Proportions

  2. What are proportions? • An equation in which two ratios are equal is called a proportion • A proportion can be written using colon notation like this • a : b :: c : d • or as the more recognizable (and useable) equivalence of two fractions. • _ a__ = _ c__ b d

  3. Proportions 6 x 5 = 3 x 10 30 = 30

  4. Proportions Determine if the following are proportions. 1) 2)

  5. Proportions 3 x 60 = 5 x 36 4 x 15 = 8 x 8 180 = 180 60 64 Yes, it is a proportion. No, it is not a proportion.

  6. Solving Proportions • 4 = 24 y 30 4(30) = 24y 120 = 24y 120 = 24y 24 24 5 = y • 1. Cross Multiply • 2. Solve for the variable.

  7. Solving Proportions • 10 = 5 y 8 8(10) = 5y 80 = 5y 80 = 5y 5 5 16 = y • 1. Cross Multiply • 2. Solve for the variable

  8. Try one on your own… • 3 = 12 y 28

  9. And another… • 6 = 12 n 24

  10. Proportions • Recall that a  fraction is always used for part-to-whole  comparison, but a ratio can be used  for  •  part-to-part comparison • part-to-whole comparison • other comparisons such as length-to-width.

  11. Proportion Word Problems • If you can buy one can of pineapple chunks for $2 then how many can you buy with $10? • First set up a proportion then solve for your variable. • Remember proportions are two equivalent ratios set equal to each other. • 1 can = x $2 $10

  12. Solving the proportion • 1 can = x cans $2 $10 • 1(10) = 2x • 10 = 2x • 10 = 2x 2 2 • 5 = x: You can buy 5 cans with $10.

  13. Proportion Word Problems • Ming was planning a trip to Western Samoa. Before going, she did some research and learned that the exchange rate is 6 Tala for $2. How many Tala would she get if she exchanged $6? • First set up a proportion then solve for your variable. • Remember proportions are two equivalent ratios set equal to each other. • 6 Tala = x Tala $2 $6

  14. Solving the proportion • 6 Tala = x Tala $2 $6 • 6(6) = 2x • 36 = 2x • 36 = 2x 2 2 • 18 = x: She would get 18 Tala.

  15. Try one on your own… • Jasmine bought 32 kiwi fruit for $16. How many kiwi can Jasmine buy if she only had $4? • First set up a proportion then solve for your variable. • Remember proportions are two equivalent ratios set equal to each other.

  16. And another… • Jenny was planning a trip to the United Arab Emirates. Before going, she did some research and learned that the exchange rate is 4 Dirhams for every $1. How many Dirhams would she get if she exchanged $5?

  17. And one more… • Shawna reduced the size of a rectangle to a height of 2 in. What is the new width if it was originally 24 in wide and 12 in tall?

More Related