Warm Ups1) A student has completed 12 out of 34 homework assignments. At this

rate, how many assignments would the student complete out of 85 assignments.

2) To make a model of the Victoria River, Zoe used 2.5 inches of clay for every 7 miles of the actual river’s length. Her model river was 50 inches long. How long is the Victoria River?

Answers:

1) 30

2) 140

4 - 4 Percents

Day 2Objective: To solve ratio word problems and problems simple interest.

Standard 5.0

Similar Triangles (worksheet)

1. A vertical flagpole casts a shadow 12 ft long at the same time that a nearby vertical post 5 ft high casts a shadow 3 ft long. Find the height of the flagpole.

Similar Triangles (worksheet)

2. A vertical rod 8 ft high casts a shadow 6 ft long. At the same time, a nearby tree casts a shadow 15 feet long. Find the height of the tree.

Try #3 with partnerTry #4 on your own

3. 4.

Finish this worksheet for homework!!

Interest

Think about these questions..

What is it?

Where/When is it earned? Why?

Now discuss your answers with a partner.

I = prt

I = Interest earned ($)p = principle (amount put in) ($)r = interest rate (as a decimal) (%)t = time (in years) (yrs)

Example 1

Find p if I = $45, r = 6%, and t = ½ year

45 = p(0.06)(.5)

45 = .03p

p = $1500

TOO1. Find p if I = $196, r = 10%, t = 7 years.2. Find r if I = $120, p = $600, t = 5

years.

Answers:

1. p = $280

2. r = 4%

Example 2

Find I if p = $1500, r = 7%, and t = 18 months

*change months to years (÷ 12)

I = 1500(.07)(18/12)I = 105(1.5)I = $157.50

TOO

1. Find I if p = $500, r = 5%, t = 6 months.

2. Find t if I = $200, p = $1500, r = 1%.

Answers:

1. I = $12.502. t = 13.3 years = 13 years 4 months

HomeworkSimilar Triangles worksheet

Pg. 219 # 40-45 all