Ratio and scale
- 1. Ratio and scale RICK DEMOLINA NCVPS
- 2. Ratio and Scales have many uses such as maps, building blue prints and even the model train you may have in your home! Eddau composed the works of "1919 Finnish Tietosanakirja ("Encyclopedia"). Scanned by Janke" and "Mike Chapman" (https://commons.wikimedia.org/wiki/File:Train_scale_4-4-0.JPG), „Train scale 4-4-0“, marked as public domain, more details on Wikimedia Commons: https://commons.wikimedia.org/wiki/Template:PD-self
- 3. Using Ratios and Scale The ratio of staff to students at a school is 3:35. There are a total of 1,520 students and staff at the school. How many students and how many staff are at the school? Notice a total quantity is given. Use scale factor. 3𝑥 + 35𝑥 = 1520 38𝑥 = 1520 𝑥 = 40 scale factor Now use the scale factor to determine the number of students and staff: Staff = 3 x = 3 ( 40 ) = 120 Students = 35(x) = 34(40) = 1,400
- 4. Using Ratio and Scale The ratio of a rectangle’s width to length is 2:3. The width is 10 inches. What is the length? Use proportions when the total is not given 𝑤𝑖𝑑𝑡ℎ 𝑙𝑒𝑛𝑔𝑡ℎ Set up ratio 2 3 = 10 𝑥 Cross multiply 2𝑥 = 3 10 Solve 2𝑥 = 30 𝑥 = 15 Answer The length of the rectangle is 15 inches