1 / 9

Understanding Scale Diagrams and Proportions in Mathematics

Learn to identify scale factors, interpret diagrams, and determine proportions in this educational guide. Practice using ratios, fractions, and percentages to understand scale in real-world objects.

bcanty
Download Presentation

Understanding Scale Diagrams and Proportions in Mathematics

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. 4.2 Scale Diagrams Learning Outcome: To be able to identify and interpret the scale factor using the scale diagram and determine if something is proportional to its original

  2. Scale • A comparison between the actual size of an object and the size of its diagram/image; can be expressed as a ratio, fraction, percent, in words, or in a diagram. • Ratio 1:2 • Fraction ½ • Percent 50%

  3. Scale Diagram • A drawing that is similar to the actual figure or object. May be smaller or larger than the actual object, but must be in the same proportions.

  4. Proportion • is a relationship that shows two ratios/rates are equal. It can be written in fraction or ratio form. Example: The ratio 1 girl to 4 students is the same as 5 girls to 20 students. As a proportion write or 1:4 = 5:20

  5. Example 1: Use the scale factor to determine the actual length of the object skateboard? The scale diagram of a skateboard uses a scale of 1:14. What is the actual length of the skateboard? Method 1: Use the Scale 5.5cm The scale 1:14 means that the actual dimensions of the skateboard are 14 times those of the diagram. Multiply the length of the skateboard in the diagram by 14. 5.5 x 14 = 77 The actual length of the skateboard is 77cm.

  6. Example 1: Use the scale factor to determine the actual length of the object skateboard? The scale diagram of a skateboard uses a scale of 1:14. What is the actual length of the skateboard? Method 2: Use a Proportion 5.5cm Set up a proportion using the scale and the measurement that is given. Scale = Note: The scale 1:14. The diagram measures 5.5 cm. The actual measurement is unknown.

  7. Show you Know The scale for the diagram of the chinook salmon is 1:9.2 Calculate the actual length of the salmon. Scale: 9.2 x 5 = 46cm

  8. Example 2: Determine the Scale Factor An actual Canadian quarter has a diameter of 23.88mm. Calculate the scale factor used to create the diagram of the quarter. Express your answer to the nearest tenth. First: Measure the diameter of the diagram of the quarter. It measures 1.4cm Second: Set up a proportion using the scale and the measurement that is given. Note: The diagram is a reduction! The scale factor will be less than 1. Scale =

  9. Assignment • Page 142 (4-11, 14,18) 5cm

More Related