6.RP.2: Understand Unit Rates
Also written as 6.RP.A.2 and CCSS.MATH.CONTENT.6.RP.A.2 · Cluster: Understand ratio concepts and use ratio reasoning to solve problems.
The Official Wording
Understand the concept of a unit rate a/b associated with a ratio a:b with b ≠ 0, and use rate language in the context of a ratio relationship. For example, "This recipe has a ratio of 3 cups of flour to 4 cups of sugar, so there is 3/4 cup of flour for each cup of sugar." "We paid $75 for 15 hamburgers, which is a rate of $5 per hamburger."
Common Core State Standards, Grade 6, Ratios & Proportional Relationships · Read it at the source · Checked October 14, 2026
What 6.RP.2 Means in Plain English
Sixth graders turn a ratio into a rate for one. If 6 notebooks cost $9, they divide 9 by 6 and say $1.50 per notebook. If a cyclist rides 30 miles in 2 hours, that is 15 miles per hour, the rate for a single hour.
In 6th grade the quantities are whole numbers, and the unit rate can be a fraction like 3/4. Rates feed into 6.RP.3, where students compare unit prices and solve constant-speed problems. In 7th grade, 7.RP.1 adds rates with fractions in both quantities, like 1/2 mile in 1/4 hour.
6.RP.2 I Can Statements
- I can find the unit rate from a ratio by dividing.
- I can say a rate with “per” or “for each”.
- I can tell which of two prices is the better deal.
6.RP.2 Worked Example
Two bags of the same apples at two prices: the unit rate is what lets students compare them at all.
A 3-pound bag of apples costs $4.50. A 5-pound bag costs $8.00. Find the price per pound for each and decide which is cheaper.
- A unit rate is the price for 1 pound, so divide the price by the number of pounds. Small bag first.$4.50 ÷ 3 = $1.50 per pound
- Do the same for the large bag.$8.00 ÷ 5 = $1.60 per pound
- Now both prices are for one pound, so they can be compared directly.$1.50 < $1.60
- Say the answer as a rate sentence, which is the language the standard asks for.The 3-pound bag costs $1.50 per pound, 10 cents less per pound.
Check it: Multiply back up: 3 × $1.50 = $4.50 and 5 × $1.60 = $8.00, both matching the prices on the bags.
Common Mistakes with 6.RP.2
Dividing the wrong way round
3 ÷ 4.50 = 0.67, so “67 cents per pound”
Try this: Ask which quantity needs to become 1. For a price per pound, pounds must be 1, so divide the dollars by the pounds.
Comparing totals instead of rates
“$4.50 is less than $8.00, so the small bag is cheaper”
Try this: Point out that the bags hold different amounts. Only the price for 1 pound makes the two bags comparable.
Dropping the units from the answer
“The rate is 1.50”
Try this: Require the full rate sentence every time, dollars per pound or miles per hour, since a number without units is not a rate.
Where 6.RP.2 Fits
Practice 6.RP.2
Quick Check
- A printer prints 180 pages in 4 minutes. What is its rate in pages per minute?
- 12 pencils cost $3.00. What is the price per pencil?
- A recipe uses 2 cups of rice for every 5 cups of water. How much water goes with 1 cup of rice?