1 / 9

Understanding Proportion

Understanding Proportion. Ratio . A ratio is the comparison of two numbers by division. A classroom has 16 boys and 12 girls. Also written as 16 boys , 16:12 or 16 to 12 12 girls Generally, ratios are in lowest terms:

hubert
Download Presentation

Understanding Proportion

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. Understanding Proportion

  2. Ratio • A ratio is the comparison of two numbers by division. • A classroom has 16 boys and 12 girls. • Also written as 16 boys, 16:12 or 16 to 12 12 girls • Generally, ratios are in lowest terms: 16 = 16/4 = 4 12 12/4 3

  3. Ratio, continued • Ratios can compare two unlike things: • Joe earned $40 in five hours • The ratio is 40 dollars or 8 dollars 5 hours 1 hour • When the denominator is one, this is called a unit rate.

  4. Ratio, continued Let’s look at a classroom: • Ratios can be part-to-part • 16 boys15 girls • Ratios can be part-to-whole • 16 boys31 students

  5. Ratio, continued • If a ratio is part-to-whole, you can divide and find a decimal or a percent. • 16 boys31 students 31/16.00 = .516, or 51.6%are boys

  6. Proportion • Proportion is a statement that says two ratios are equal. • In an election, Damon got three votes for each two votes that Shannon got. Damon got 72 votes. How many votes did Shannon get? • Damon 3 = 72 so 3 x 24 = 72 Shannon 2 n 2 x 24 48 n = 48, so Shannon got 48 votes.

  7. Proportion, continued • Tires cost two for $75. How much will four tires cost? • # of tires2 = 4 so 2 x 2 = 4 tires cost 75 n 75 x 2 $150 n = 150, so four tires cost $150

  8. Proportion, continued • One more way to solve proportions: • 2 = 62 x n = 6 x 82n = 488 n 2 2 n = 24

  9. Proportion, continued • Now you try! • Three cans of soup costs $5. How much will 12 cans cost? • # of cans3 = 123 x 4 = 12 cans cost 5 n 5 x 4 20 dollars n = 20, so 12 cans cost $20

More Related