Grade 5

Encourage students to find more than one possible answer.

Margaret found a common denominator of 24 when she added two fractions. What might the denominators of the fractions she was adding have been?

- The denominators could be 6 or 4. (However, for sixths and fourths there is a smaller common denominator that you could use: 12.)
- If the denominators were 8 and 3, then 24 would be the smallest common denominator.
- They could be 6 and 24, or they could be 8 and 12.

To extend this Headline Story, you might ask students if either of the denominators could be greater than 24. (Yes, if the fraction is not yet in simplest form.)

This work is licensed under a

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.