1. SWBAT… calculate ratio and proportion problems
Tues, 9/6
SWBAT… calculate ratio and proportion problems
Agenda
WU (10 min)
Notes on ratios & proportions – 2 slides (15 min)
Practice problems – 3 examples (10 min)
Work on HW#9 (10 min)
WU: Solve each equation (show all your work!):
HW#8-Ratio & Proportions

2. Definition: A ratio is a comparison of two numbers by division.
Topic: Ratios and Proportions
Definition: A ratio is a comparison of two numbers by division.
Picture: The ratio of x to y can be expressed in the following ways:
x to y, x:y,
Examples: 3 to 7, 3:7,

3. Proportion (7)(48) = (42)(8) 336 = 336
Definition: A proportion is an equation that states two ratios are equal.
Picture/Example:
To determine whether pairs of ratios are equivalent, use cross products
Or, cross multiply
The cross products are equal, so the ratios do form a proportion and therefore the pair of ratios are equivalent.
(7)(48) = (42)(8)
336 = 336
(Prob #2 on the HW#9)

4. Directions: Solve the proportion.
Example 1:
n(27) = 6(9)
27n = 54
n = 2
(Prob #4 on the HW#9)

5. Example 2:
Write a proportion with one unknown variable.
Solve for the unknown variable.

6. `
Example 2:
A restaurant made $545 in profit from selling 110 hamburgers. If they sold 53 hamburgers during lunch, what was their profit?

7. SWBAT… calculate ratio, proportions, time, and conversions
Wed, 9/7
SWBAT… calculate ratio, proportions, time, and conversions
Agenda
Quiz (10 min)
Time conversions (30 min)
Quiz: Complete on a sheet of paper (collected)
Solve each proportion:
3. Mr. V can run 10 miles in 1.5 hours, how long (in hours and minutes) will it take him to run a marathon (26 miles) at the same speed.
HW#9-Time conversions

8. HW#9 Answers No
Yes
n = 2
u = 5
b = 3.75
t = 0.57