6.RP.3: Solve Ratio, Rate and Percent Problems
Also written as 6.RP.A.3 and CCSS.MATH.CONTENT.6.RP.A.3 · Cluster: Understand ratio concepts and use ratio reasoning to solve problems.
The Official Wording
Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.
Common Core State Standards, Grade 6, Ratios & Proportional Relationships · Read it at the source · Checked October 14, 2026
What 6.RP.3 Means in Plain English
This is the workhorse standard of 6th grade. Students fill in ratio tables and plot the pairs, find unit prices and speeds, take a percent of a number (30% of 50 is 15), find the whole from a part and a percent, and convert units like feet to inches.
The tools matter as much as the answers: tables of equivalent ratios, tape diagrams and double number lines, not cross-multiplying. Proportions as equations wait for 7th grade, where 7.RP.3 solves multistep percent problems like tax, discount and percent change, and 7.RP.2 names the constant of proportionality.
6.RP.3 I Can Statements
- I can complete a ratio table and plot its pairs.
- I can find a percent of a number and the whole from a part.
- I can convert units with a ratio, like 3 feet to 36 inches.
6.RP.3 Worked Example
A percent problem run backwards: the part and the percent are known, the whole is not, and a double number line finds it without a formula.
Maya has read 60 pages, which is 40% of her book. How many pages does the book have?
- Draw a double number line: percents on top from 0% to 100%, pages underneath. Mark 40% directly above 60 pages.0% ... 40% ... 100% over 0 ... 60 ... ?
- Find what 10% is worth. 40% is four 10%s, so divide 60 by 4.60 ÷ 4 = 15 pages per 10%
- The whole book is 100%, which is ten 10%s.10 × 15 = 150 pages
- Write the same reasoning as a ratio table, so students see both tools agree.40% : 60 pages, 10% : 15 pages, 100% : 150 pages
Check it: Take 40% of 150: 40/100 × 150 = 60 pages, the part we started with.
Common Mistakes with 6.RP.3
Taking the percent of the part
40% of 60 = 24, so “the book has 24 pages”
Try this: Ask whether the answer should be bigger or smaller than 60. The whole book is more than 60 pages, so 24 cannot be right.
Scaling one column of a ratio table
3 lawns in 7 hours, so 6 lawns in 7 hours
Try this: Multiply both quantities by the same number, every row. Doubling the lawns doubles the hours too: 6 lawns in 14 hours.
Converting units in the wrong direction
5 feet = 5 ÷ 12 inches
Try this: Write the conversion as a ratio first, 12 inches for every 1 foot, so 5 feet is 5 × 12 = 60 inches.
Where 6.RP.3 Fits
Practice 6.RP.3
Quick Check
- A machine fills 6 bottles in 4 minutes. At that rate, how many bottles does it fill in 30 minutes?
- What is 30% of 80?
- 18 is 25% of what number?