1. Math For Life Situations Vicki Angel Manuel A. Navarro

2. 1. Understand Ratios 2. Offer instructors an effective, easy, relevant way to teach percents using the proportion method

3. WHAT IS A RATIO? COMPARISON BETWEEN TWO QUANTITIES OR NUMBERS. 4 puzzle parts to 3 gears WHAT IS THE RELATIONSHIP BETWEEN THEM? For every 4 puzzle parts, there are 3 gears.

4. RATIOS CAN BE WRITTEN IN 3 DIFFERENT WAYS: · 4 to 3 · 4 : 3 · 4 / 3

5. More about ratios Ratios can be reduced by division. Example: 6 / 4 = 3 / 2 when divided by 2 / 2 Ratios can be increased by multiplication. Example: 6 / 4 = 18 / 12 when multiplied by 3 / 3 Order is important. Example: 4 full time to 5 part time workers it is not the same as 5 part time to 4 full time workers

6.  What is a proportion?  In a proportion there are 2 ratios combined by the equal sign ( = ).  This makes both ratios equivalent

7.  For example:  30 to 6 = 5 to 1  How do we know?  By cross multiplication 30 X 1 = 6 X 5 30 = 30

8. How do you introduce Percents? 1. What is 20% of 40? 2. 45 is 45% of what number? 3. 35 is what percent of 70? 4. Students get confused on how to solve these problems!

9. 1. When do I multiply? 2. When do I divide? 3. How do you multiply or divide with percents? 4. Please, give me an easy way to do it! 5. The answer is a PROPORTION!

10.  All percent problems are composed of three parts ◦ Percent ◦ Part ◦ Whole  The answer lies in identifying which one is missing.

11. is of % 100

12.  Start with teaching students how to identify the three components using CLUE WORDS ◦ Is – defines the part, or portion ◦ Of – defines the whole or original amount ◦ % symbol – defines percent

13. 8 is 20% of 40  Clue Words ◦ IS = Part, portion. ◦ % = Percent Symbol ◦ OF = Whole, original.

14. 8 is of % 100 is 20% of40 100 IS OF %

15. 2 & 3 Pages Do

16. What is 20% of 40? 40 ? 20% 100 Cross Multiply 100 8 20 X =800 Divide by the other number =8 800 ÷

17. 8 8 is 20% of what number? ? 20% 100 Cross Multiply 40 X =800 ÷= 8 100 Divide by 3 rd. Number 20 40

18. 8 8 is what % of 40? 40 ? % 100 Cross Multiply 20 X =800 ÷= 8 100 40 Divide by 3 rd. Number 20 %

19. 4 - 6 Pages Do

20. 1. Multiplication? Division? 2. Eliminates the need to convert percent into decimals. 3. Introduces students to variables. 4. Fractions, Unit conversions and Geometry applications.

21. 1. Q & A. Are there any questions? 2. Do you have any suggestions? 3. Do you think this is something you can use? THANK YOU!