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Finding Unit Rates When Quantities Are Fractions: Grade 7 Math Lesson

Last updated: October 22, 2026 · Written by the Math Made Easy math teachers

Grade 7 Math Lessons – Mathbot, the Math Made Easy robot coach, with free printable lessons for Grade 7

Looking for unit rates with fractions 7th grade? Then this Grade 7 lesson on Finding Unit Rates When Quantities Are Fractions explains each idea step by step, with worked examples.

Quick answer: A unit rate with fractions tells how much of one quantity matches exactly 1 unit of another when the measurements are fractions. Divide the first quantity by the second, multiply by the reciprocal of the divisor, and simplify. For example, 1/2 mile in 1/4 hour is 2 miles per hour.

Standards: 7.RP.A.1 · Level: Grade 7

What is a unit rate when the measurements are fractions?

A unit rate says how much of one quantity matches exactly 1 unit of another quantity. When the measurements themselves are fractions, the rate is written as a complex fraction, a fraction whose top and bottom are fractions.

Unit rate

A unit rate compares two quantities so that the second quantity equals 1. Examples: miles per hour, dollars per pound, cups per batch, square feet per minute.

How do you simplify a complex fraction?

A fraction bar means division. So a complex fraction is a division of two fractions, and dividing by a fraction means multiplying by its reciprocal.

Rate formula

abcd = ab ÷ cd = ab × dc

The quantity on top of the fraction bar is the one being measured; the quantity on the bottom is the one that becomes 1.

5/6 milein 3/8 hour5/6 × 8/340/18 = 20/92 2/9 milesper hour
Turning a fractional rate into a unit rate: divide, which means multiply by the reciprocal.
Method: finding a unit rate from fractions

  1. Decide which quantity is measured and which one should become 1 (the word after "per").
  2. Write the quantities as a division, first quantity ÷ second quantity.
  3. Change any mixed numbers to improper fractions.
  4. Multiply by the reciprocal of the second fraction.
  5. Simplify and write the answer with its unit.
Worked example

A kayaker paddles 56 mile in 38 hour. Find the speed in miles per hour.

56 ÷ 38 = 56 × 83 = 4018 = 209 = 2 29. The unit rate is 2 29 miles per hour.

Time (hours)3/81Distance (miles)5/620/9
Both rows are multiplied by 8/3, so the time becomes exactly 1 hour.

What if the two quantities use different units?

Compute the rate in the units you are given, then convert. A rate in miles per minute becomes miles per hour when multiplied by 60, because 1 hour has 60 minutes.

1/4 milein 3 minutes1/4 ÷ 3= 1/12 mi per min1/12 × 60minutes per hour5 milesper hour
Different units: find the rate per minute first, then convert minutes to hours.
Common mistake

Dividing in the wrong order. For 14 mile in 3 minutes, 14 ÷ 3 gives miles per minute, but 3 ÷ 14 gives minutes per mile. Say the rate aloud, "miles per minute", to pick the order.

Mathbot’s tip

Check your answer by multiplying it back: unit rate × second quantity should return the first quantity. If 2 29 × 38 gives 56, you are right.

Key points to remember

  • A unit rate has 1 in the denominator: miles per 1 hour, dollars per 1 pound.
  • A complex fraction is just a division of two fractions.
  • Dividing by a fraction means multiplying by its reciprocal.
  • When units differ, convert after finding the rate (for example, multiply by 60 to go from minutes to hours).
  • Multiplying the unit rate by the second quantity must give back the first quantity.

Finding Unit Rates When Quantities Are Fractions: frequently asked questions

What is a complex fraction?

A complex fraction has a fraction in its numerator, its denominator, or both. It is read as a division: the top fraction divided by the bottom fraction.

Why do we multiply by the reciprocal?

Dividing by a fraction asks how many of that fraction fit into the amount. Multiplying by the reciprocal gives the same result and is faster, because the reciprocal of 3/8 is 8/3.

How do I know which quantity to divide by?

Look at the word after per. In miles per hour, hours is the quantity that becomes 1, so divide miles by hours.

Can a unit rate be a fraction or a mixed number?

Yes. A unit rate can be any positive rational number, such as 2 2/9 miles per hour or 3/4 cup per batch.

How do I find a unit rate when the units are different?

Divide the quantities as given, then convert with a conversion factor such as 60 minutes per hour or 3 feet per yard. Check that the final unit matches the question.

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