Proportional Reasoning

Proportional Reasoning

What are proportions?

Proportions are a comparison of two ratios. They are equivalent ratios.

We get a proportional relationship from multiplying each value by the same number (Constant of Proportionality)

Multiple Choice

What are proportions?

• A letter in an equation

• A comparison of two quantities

• A comparison of ratios (Equivalent ratios)

• Constants

How do we tell if ratios are proportional?

Multiple Choice

Are these two ratios proportional? $$\frac{3}{2}\ and\ \frac{9}{4}$$

• Yes

• No

Ratio Tables

Ratio tables list equivalent ratios.

We can fill in missing values by multiplying both numbers in the ratio by the same number.

Multiple Choice

Fill in the missing value of the ratio table.

• 15

• 20

• 4

• 10

Unit Rate

Unit rate means "how much for 1 of something."

We can find our unit rate by dividing ______ per _______, whatever the problem says.

MONEY ALWAYS GOES ON TOP!!!!!!

Ex: Daniel drove 300 miles on 15 gallons of gas. How many miles did he drive per gallon?

Multiple Choice

Kaison is making banana bread. He can make 4 loaves of bread with 3 cups of flour. How man cups of flour does he need to make 1 loaf of bread?

• 1.33

• 0.75

• 3

• 4

Graphing Proportional Relationships

Proportional Graphs MUST pass through the origin (0,0) AND be a straight line.

Multiple Choice

Is this graph proportional?

• Yes, because it ONLY goes through the origin

• No, because it is not a straight line.

• No, because it does not go through the origin.

• Yes, because it is a straight line AND goes through the origin.