CCSS.Math.Content.4.NF.B.3d
The Standard
Solve word problems involving addition and subtraction of fractions referring to the same whole and having like denominators, e.g., by using visual fraction models and equations to represent the problem.
Common Core State Standards for Mathematics
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students decide whether a fraction story calls for addition, subtraction, or both. They use a drawing and an equation to show how the parts relate to one whole.
What Mastery Looks Like
- Students choose the correct operation, draw an accurate fraction model, and write a matching equation. They keep the denominator unchanged and label the answer with the correct unit.
Common Misconceptions
- Students may add or subtract the denominators along with the numerators. They may also overlook whether each fraction refers to the same whole or choose an operation from keywords alone.
How to Assess It
- Give this exit ticket: “A ribbon is 8/8 meter long. Luis uses 3/8 meter, then 2/8 meter. How much is used, and how much remains?” Require a drawing and two equations.
Lesson moves
Ways to Teach It
Give pairs paper strips marked in eighths, then have them act out a ribbon story and record each step with an equation.
Ask students to explain in writing why the denominator stays the same when adding 3/8 and 2/8.
Create card sets with fraction stories, bar models, equations, and answers, then have groups race to build matching sets.
Have students plan one liter of fruit punch using fractional amounts, then find the total used and the amount left.
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Printable 4.NF.B.3d Worksheet
A ready-to-print activity worksheet aligned to CCSS.Math.Content.4.NF.B.3d, with an answer key for the teacher on its own page. No account needed.
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Download the worksheetLearning progression
Where This Standard Sits
Before This Standard
If students are struggling here, check these first.
- CCSS.Math.Content.4.NF.B.3
Students must see fractions as counts of unit fractions to add or subtract like denominators in word problems.
- CCSS.Math.Content.4.NF.B.3a
Word problems require interpreting fraction addition and subtraction as joining or separating like-sized parts of the same whole.
- CCSS.Math.Content.3.NF.A.1
Adding or subtracting like denominators relies on seeing a/b as counts of same-size unit fractions from one whole.
What This Unlocks
Mastery here sets students up for these next.
- CCSS.Math.Content.4.MD.B.4
Adding and subtracting fractional measurements in line plot questions uses the same like-denominator fraction reasoning from word problems.
- CCSS.Math.Content.5.NF.A.2
Like-denominator fraction word problems carry over the same whole, models, equations, and reasonableness checks before adding unlike denominators.
Keep exploring
Related Standards
- CCSS.Math.Content.6.NS.A.1
Interpret and compute quotients of fractions, and solve word problems involving division of fractions by fractions, e.g., by using visual fraction models and eq...
- CCSS.Math.Content.4.NF.B.4c
Solve word problems involving multiplication of a fraction by a whole number, e.g., by using visual fraction models and equations to represent the problem.
- CCSS.Math.Content.5.NF.B.6
Solve real world problems involving multiplication of fractions and mixed numbers, e.g., by using visual fraction models or equations to represent the problem.
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