Ratios

Ratios

Let's take a deeper look into what ratios really are about

They compare things so you can see how they match up to each other.​

Ratios

Multiple Choice

What are ratios?

• Random fractions

• at least 2 numbers being compared

• Division

• Witch craft by mathemagicians

Ratios compare at least 2 numeric values to each other

Like the number of girls to boys in a class.

The amount you pay for fruits when weighted.

The number of bags of Takis to the amount paid.​

​When comparing order is important

​How something is said determines the ratio order.​

Multiple Choice

In a class there are 20 boys and 15 girls. The ratio of girls to boys is

• 20:15

• 20:10

• 15:20

• 10:20

Your answer should have:

​

number of dogs : number of cats.

​If you are asked for dogs compared to cats.

Multiple Choice

At the zoo, Steve counted 4 tigers for every 5 lions and 3 elephants for ever 4 giraffes. Which is the ratio for lions to tigers?

Select all the apply.

• $$5:4$$  

• $$4:5$$  

• $$3:4$$  

• $$4:3$$  

Multiple Choice

According to the recipe for pie crust, what is the ratio of flour to fat?

(fat is butter or oil)

• $$2:1$$  

• $$3:2$$  

• $$3:1$$  

• $$1:3$$  

​Comparing at least 2 values to each other, in which order is of the utmost importance.

​

Grandma drove the car not the car drove grandma​

​​Ratio

​​Equivalent Ratios

Multiple Choice

Which of the following are equivalent to $$5:12$$  ?

• $$15:12$$  

• $$5:24$$  

• $$10:24$$  

• $$12:5$$  

​A scale factor is what the ratio is increasing by, like:

​

• When we say to double, we are using the scale factor of ____.

  ​

• Or when we say triple, we are using the scale factor of _____.​

​

Ratios and their scale factors

Multiple Choice

At Addie's Pet Shop there are 3 cats to every 7 dogs what is the scale factor if there is a total of 30 pets?

• $$7:3$$  

• $$3:7$$  

• $$3$$  

• $$5$$  

Multiple Choice

At the aquarium Billy counted 3 sharks to every 8 penguins, if the ratio was only a third of the actual amount what is the real number of sharks to penguins?

• $$9:24$$  

• $$6:16$$  

• $$24:9$$  

• $$16:9$$  

Scale Factors can shrink too.

When we use a scale factor to reduce the ratio like 10:12 can be reduced to a ratio of 5:6

​

In this case the ratio has a scale factor of 1/2​

Multiple Choice

Jeff is making cookies that use 3 cups of flour for every 2 teaspoon of vanilla. If Jeff had 6 teaspoons of vanilla how much flour will he need?

• 10 cups

• 12 cups

• 9 cups

• 6 cups