Notes

1
Notes 1 Proportions (section 3.9)

• A. Review
• Solve with the butterfly
• 1.) 2.)
• 3.) 4.)

2
B. Word Problems that compare two quantities

• Find the two things that are being compared
• Write in words one on top of the other
• Write a proportion ____ ____ that matches
  these words
• Fill in the unknown spot with a variable
• Butterfly and solve!
• Ex
• Mrs. Spraggs car can travel 126 miles on two
  gallons of gas. How far can her car travel on 7
  gallons of gas?

3
Write a proportion to solve

• 1.) On a certain map, 3 inches represents 5
  miles. How many miles are represented by 8
  inches?
• 2.) On a school field trip, 2 adults accompany
  every group of 13 students. How many adults are
  needed on a field trip of 65 students?

4

• 3.) A survey of 120 people in a city found that
  their favorite pizza was Papa Johns. If this
  survey is representative of the citys population
  of 100,000, about how many people favor Papa
  Johns?
• 4.) Mrs. Spraggs math students can solve 3
  equations in 8 minutes. How many equations can
  they solve in 1 hour?

5

• 5.) The ratio of boys to girls at Canyon Crest
  is 45. If there are 480 boys here, how many
  girls are here? How many students go to Canyon
  Crest in total?
• 6.) A recipe for chocolate chip cookies asks for
  2 cups flour and 1 cup sugar. If you want to
  make more cookies and use 3 cups of flour, how
  much sugar do you need?

6

• Review
• 1.) Solve -3x 1 2(x 6)
• 2.) Twice the sum of a number and three is the
  same as one less than the number. Write an
  equation and find the number.