🧮 Ratios — Understanding Ratios and Ratio Language
Descend into the Midnight Abyss with Captain Coral!
Read the Passage First!
🔤 Words to Know
Ratio — A comparison of two quantities, written as a:b, a to b, or a/b.
Equivalent ratios — Ratios that represent the same relationship, like 2:3 and 4:6.
Rate — A ratio that compares two different units, like miles per hour.
Captain Coral and Wanda were cataloging species in the hydrothermal vent field. They found that for every 3 anglerfish, there were 5 lanternfish.
"That relationship is called a ratio," said Wanda. "We can write it as 3:5, 3 to 5, or 3/5."
"The ratio tells us that anglerfish and lanternfish appear in a consistent pattern," Wanda continued. "If we find 6 anglerfish, we would expect to find 10 lanternfish. That is an equivalent ratio — we multiplied both parts by 2."
Captain Coral practiced: "If the ratio of red coral to blue coral is 4:7, and I find 12 red coral, how many blue should there be? 4 times 3 = 12, so 7 times 3 = 21 blue coral."
"Ratios can also be part-to-whole," said Wanda. "If 3 out of every 8 fish are anglerfish, the ratio of anglerfish to total fish is 3:8."
Captain Coral noticed something else: "A rate compares different units. We are finding 12 species per hour. That is a rate!"
"Ratios are the foundation of proportional reasoning," said Wanda. "They appear everywhere in science, cooking, maps, and business. In sixth grade, you will use them constantly."
🧠 Answer the Questions
Read carefully and support your answers with evidence!
What is a ratio?
How can you write the ratio 3 to 5?
If the ratio is 3:5 and there are 6 anglerfish, how many lanternfish?
What are equivalent ratios?
Ratio of red to blue coral is 4:7. If 12 red, how many blue?
What is a rate?
What is a part-to-whole ratio?
If ratio is 2:3 and first quantity is 10, find the second.
Write an equivalent ratio for 5:8.
Where do ratios appear in real life?
12 species per hour is what type of ratio?
3 out of 8 fish are anglerfish. What ratio is anglerfish to total?
What is the ratio of lanternfish to anglerfish if anglerfish:lanternfish is 3:5?
If 3:5 = 9:?, what is the missing number?
Why are ratios foundational for sixth grade?