1 / 6

Lesson 2.3 Proportional Reasoning

Lesson 2.3 Proportional Reasoning. Definitions and Examples. A proportion is an equation between two ratios or rates. Example 1. $ 2.85 = $0.95 3 pencils 1 pencil To prove this, take your caluculator and go $2.85/3. You will get $0.95 so there for this is an equation.

dougal
Download Presentation

Lesson 2.3 Proportional Reasoning

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. Lesson 2.3 Proportional Reasoning

  2. Definitions and Examples A proportion is an equation between two ratios or rates

  3. Example 1 $2.85 = $0.95 3 pencils 1 pencil To prove this, take your caluculator and go $2.85/3. You will get $0.95 so there for this is an equation.

  4. Example 2 Solve the following proportions… 1cm : 25km = 4cm: ? First term is multiplied by a factor of 4, so the second term is multiplied by 4 25x4=100, so the answer is 100km

  5. Example 3 200 km = ? 3h 5h Two methods to solving 1. Method 1: Find the unit rate and multiply as needed 200km/3h = 66.666km/h or 66.66km per one hour 66.666km/h x 5 hours = 333.3333km 2. Method 2: Cross-multiply and divide 200km x 5h /3h = 333.333km

  6. Example 4 Use a proportion to solve…. Two out of three dentists recommend chewing sugarless gum after eating to prevent cavities. If there are 60 dentists in Stickyville, how many of them would you expect to recommend chewing sugarless gum after eating to prevent cavities? Step 1: Set up the proportion 2 = ? 3 60 dentists Step 2: Choose method unit rate or cross-multiply 3 x 20 = 60 2x 20 = 40 Therefore, 40 dentists in Stickyville would recommend chewing sugarless gum after eating to prevent cavities.

More Related