Welcome to Math 6

1. Welcome to Math 6 Proportional Reasoning Spectacular

2. Objectives Use ratio and rate reasoning to solve real-world and mathematical problems.

3. Connector • Proportional reasoning involves simple fractions, ratios, and probabilities. • It is used by: • People comparing grocery prices • Economists comparing population densities, • Architects making scale models, • Chemists determining the relative strength of solutions.

4. Review A ratio is a relationship between two values. For instance, a ratio of 1 pencil to 3 pens would imply that there are three times as many pens as pencils. For each pencil there are 3 pens, and this is expressed in a couple ways, like this: 1:3, or as a fraction like 1/3.

5. Review A proportion is two ratios that have been set equal to each other; a proportion is an equation that can be solved.

6. Review Solving a proportion means that you are missing one part of one of the fractions, and you need to solve for that missing value.

7. If a doctor prescribes 500 ml medicine to be administered over 2 hours, how many drops per minute should be administered if the set is calibrated to deliver 20 drops per ml? Problem 1

8. If I clean a 2400 square foot building five nights per week for a sum of $960 per month, what is the cost per square foot? Problem 2

9. When eggs went from 17 to 39 cents, by what percent did the price increase? Problem 3

10. If you can run 100 meters in 10 seconds, how long would it take you to run 1,728,000 meters? Problem 4

11. Conclusion Working with proportions is certainly one of the most powerful skills that you can acquire. It relates to so many other math topics and can be used in a wide array of real-life problem-solving.

12. Assignments • Play the quiz game at the web address below: http://www.quia.com/rr/97979.html