Adding and Subtracting Fractions Word Problems With Unlike Denominators
Teach common denominators as a way to work with equal-sized pieces.
Teaching notes for parents and teachers
How to teach it
Keep one foot as the reference whole and draw both fractions on matching strips. Rename them before combining or subtracting.
Example to work through together
Use the model below as you explain the example. Have your student point to the quantities as you discuss them.
1/2 + 1/3 = 3/6 + 2/6 = 5/6 foot
The bars use the same whole and the same-sized sixths. Splitting one half into three sixths, or one third into two sixths, changes the way the length is named, not the amount of cable.
Green shows the original 8/12 cup. Orange shows the added 6/12 cup. Each full bar is one cup, so the fourteen colored parts fill one whole cup and two twelfths of the next.
Ask your student
How can we make the pieces the same size without changing either length?
If your student needs help
If only the denominator changes, count how many new pieces replace each original piece.
Make a practice set
Select the worksheet, answer key, or both. When both are selected, the answer key prints after the questions. Keep it separate if you want your student to work independently.
After your student finishes
Ask the child to name the one-foot whole, explain the operation, and show why the equivalent fractions have the same value. Check the estimate and unit as well as the arithmetic. Use like-denominator stories first when counting equal-sized parts still needs practice.
Calculation practiceAdding Fractions With Like Denominators
Add equal-sized parts; simplify sums that may be greater than one.
12 problems · Answer key included
Calculation practiceSubtracting Fractions With Like Denominators
Take away equal-sized parts of the same whole and simplify the difference.
12 problems · Answer key included
Word problemsAdding and Subtracting Fractions Word Problems With Like Denominators
Combine or remove fractional cable lengths measured using the same one-foot whole.
4 problems · Answer key included
More about fractions · Grade 5 worksheets
Grade 5 selected skill connection: 5.NF.A.1; 5.NF.A.2 (one-step cable-length stories with unlike written denominators). See the Common Core standards for this grade. This worksheet does not cover every requirement in the standard.