1. Ratios Lesson 7 – 1

2. Vocabulary Ratio: a comparison of two numbers (quantities) by division Equivalent Ratios: ratios showing the same relationship between two quantities. (have the same value)

3. How to write a ratio? 3 ways! Example: ratio of 5 girls to 3 boys 5 to 3 5:3 Also possible with algebra, a to b a to b a:b 3 5 b a

4. Need to Know about Ratios! # 1:order matters. Follow the order from the question. # 2:label your work. This will help when you set up proportions. # 3: write the ratio in simplest form! # 4: DON’T change to mixed numbers. It is ok to have improper fractions when writing a ratio.

5. Practice writing ratios In the SMS choir, there are 24 sopranos, 2 tenors, 4 basses, and 15 altos. Find each ratio. # 1:What is the ratio of tenors to sopranos? # 2:What is the ratio of altos to members in the choir? # 3:What is the ratio of sopranos to altos? 12 1 3 1 5 8

6. Rates Lesson 7 – 2

7. Vocabulary Rate: a ratio that compares two quantities measured in different units Unit Rate: a rate simplified to a denominator of 1 unit. Example: I can type 200 words in 4 minutes My Rate = Unit Rate = 4 minutes 200 words 1 minute 50 words

8. ‘per’ means to ‘divide by’ Example: miles per hour means to divide number of miles by number of hours. So, if you drive 360 miles in 8 hours, and you want miles per hour, then: Answer: 45 miles per hour or 45 mph 360 miles8 hours

9. Find the Better Buy! Find the unit rate to determine the better buy. # 1:5 pairs of socks for $4.95 8 pairs of socks for $7.95 #2:4 CDs for $60 6 CDs for $75 5 CDs for $70 3 CDs for $40 5 pairs for $.99 per pair 6 CDs for $12.50/ CD $13.33/CD $14.00/CD $12.50/CD $15.00/CD $0.994/pair $0.99/pair