About this video
A ratio compares two quantities, and can be said as "a to b". The video finds ratios from a table of ride queues, a list of Katie's books and a picture of apples and bananas, and stresses that the order of a ratio matters.
You'll be able to
- write a ratio comparing two quantities from a table, a list or a picture.
- put the quantities in a ratio in the order the question asks for.
- explain a ratio in words using "for every".
Key words
- ratio
- A comparison of two quantities, such as 11 to 4, meaning for every 11 of one thing there are 4 of another.
- for every
- A way of saying a ratio in words, like "for every 3 apples there are 4 bananas".
Transcript
- [Instructor] Let's do some example questions dealing with ratios. So we're told, "The table shows the number of people waiting "in line for different rides at an amusement park." So 15 people are waiting in line for the roller coaster, four people for the slingshot, 12 people waiting in line for the bumper cards, and 11 people in line for the round-up.
"What is the ratio of people waiting in line "for the round-up "to the people waiting in line for the slingshot?" Pause this video and see if you can figure it out. So we wanna know the ratio of the people waiting in line for the round-up, this is the round-up right over here, to the number of people waiting in line for the slingshot.
So, there's 11 people waiting in line for the round-up, and there are four people waiting in line for the slingshot, so the ratio is 11 to four. Or for every 11 people in line for the round-up, there are four people waiting in line for the slingshot. Let's do another example.
"Katie loves to read! "In the last few months, she has read three graphic novels, "two mysteries, four science fiction novels, "and 21 comic books. "What is the ratio of sci-fi novels to comic books?" So once again, pause this video and try to work it out on your own.
All right, so we wanted to know the ratio of sci-fi novels, so she has four sci-fi novels, the ratio of that to comic books. She has 21 comic books. So the ratio is for every four sci-fi novels, she has 21 comic books. Do you want me to do that in that other color?
She has 21 comic books. So the ratio is four to 21, the ratio of sci-fi novels to comic books. Four sci-fi novels for every 21 comic books. Let's do one more example. This is strangely fun. "What is the ratio of apples to bananas?" Pause this video and try to figure it out.
So let's see, there are one, two, three apples. So for every three apples, how many bananas are there? Well, there's one, two, three, four bananas. So the ratio of apples to, the ratio of apples to bananas is three apples for every four bananas. Order matters.
If they said the ratio of bananas to apples, then this would be four to three, but they say apples to bananas, three to four. Three apples for every four bananas.
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