Math 2 Focus Topic 2 Review

Math 2 Focus Topic 2 Review

Lessons 2-1 & 2-2 :: Connect Ratios, Rates, and Unit Rates | Determine Unit Rates with Ratios of Fractions

A RATIO is a relationship in which for every x units of one quantity there are y units of another quantity.

A RATE is a RATIO that relates two quantities with different units. An UNIT RATE relates a quantity to 1 unit of another quantity.

You can use what you know about equivalent fractions and calculating with fractions to write a RATIO of fractions as an UNIT RATE.

Multiple Choice

Mealworms are a healthy food for wild

songbirds. Adam buys a 3.5-oz container of

mealworms for $8.75. Marco buys a 3.75-oz

container of mealworms for $9.75. Which

container is the better deal? *Be sure to explain your thinking.*

• Adam's container has the better deal.

• Marco's container has the better deal.

• Adam's container is the better deal because his costs $2.50/ounce.

• Marco's container is the worse deal because his container costs $2.15/ ounce

Lesson 2-3 :: Understand Proportional Relationships: Equivalent Ratios

Two quantities x and y have a PROPORTIONAL RELATIONSHIP if the ratios  $\frac{x}{y}$  for every related pair of x and y are equivalent. You can write a PROPORTION to show that two ratios have the same value.

Multiple Choice

Look at the graph to answer the following questions.

Are the perimeter and the side length of

squares proportional?

• No, the sides of a square are all different and not a proportion.

• No

• Yes

• Yes, the perimeter and the side lengths are proportional because all sides of a square are equivalent

Fill in the Blanks

Lesson 2-4 :: Describe Proportional Relationships: Constant of Proportionality

The equation y= kx describes a proportional

relationship between two quantities; x and y, where k is the CONSTANT OF PROPORTIONALITY. k = y/x for any related pair of x and y ; except when x = 0

Multiple Choice

Sally is going on vacation with her family. In 2 hours they travel 90.5 miles. If they travel at the same speed, write an equation that represents how far they will travel, d, in h hours.

• 45.25

• d = 45.25h

• h = 90.5d

• 90.5 x 2 = 181

Fill in the Blanks

Lesson 2-5:: Graph Proportional Relationships

The graph of a proportional relationship is a straight line through the origin. You can identify the constant of proportionality, k, from the point (1, k) or by dividing y/x for any point (x , y) ; except the origin.

Multiple Choice

Does the graph show a proportional relationship? Explain.

• Yes, because it is a straight line.

• No, because it is not a straight line.

• Yes, because the line passes through the point of origin (0,0)

• No, because the line does not pass through the point of origin (0,0)

Lesson 2-6 ::: Apply Proportional Reasoning to Solve Problems

Think about how two quantities are related

before you decide to use proportional

reasoning to solve a problem.

Multiple Select

Decide which problems can be solved by using proportional reasoning. Select all that apply.

• Yani buys 4 dozen flyers for $7.25. What is

  the cost of 12 dozen?

• First-class letters cost $0.49 for the first

  ounce and $0.22 for each additional ounce.

  What is the cost of a 5-oz letter?

Multiple Choice

Does the graph show a proportional relationship? Explain.

• Yes, because it is a straight line.

• No, because it is not a straight line.

• Yes, because the line passes through the point of origin (0,0)

• No, because the line does not pass through the point of origin (0,0)

Well done!!