What this worksheet covers
Multiplying fractions needs no common denominator: multiply the tops, multiply the bottoms, and simplify. Each problem here has two proper fractions with denominators from 2 to 9, so the product is always smaller than either factor, which surprises students who expect multiplication to make things bigger. The key gives every answer in lowest terms, and some problems simplify a good deal.
Who it is for
Fifth grade. Common Core 5.NF.B.4 asks students to multiply a fraction by a fraction and to interpret the product as a part of a part, with area models. Students need to simplify fractions to be able to read the key.
Multiplying two proper fractions · grade 5
A worked example
2/3 × 3/4. Multiply the tops: 6. Multiply the bottoms: 12. The result is 6/12, which simplifies to 1/2. A shortcut is to cancel the 3 on the top and bottom before multiplying, which gives 2/4 and then 1/2.
Mistakes to watch for
- Finding a common denominator first, as for addition, then multiplying across the wrong way. Remind students that multiplication does not need one.
- Forgetting to simplify, so 6/12 is left as it stands. Ask whether any number divides both.
Make it your own
This sheet is one setting of the math worksheet generator. Open it there to change the skill, the range of numbers or the heading, or to mix several skills on one sheet.