Standard: 4.NF.B3d – 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.
Grade level: Grade 4
Subject: Mathematics
Domain: Numbers & Operations – Fractions
Teacher Overview
This standard focuses on solving word problems that involve the addition and subtraction of fractions with like denominators. It is important because it builds on students’ understanding of fractions and prepares them for more complex operations with fractions in later grades. Students should have a solid understanding of basic fractions and be able to perform simple addition and subtraction. They should also be comfortable using visual models to represent fractions.
After mastering this standard, students will be able to tackle more complex fraction operations, such as adding and subtracting fractions with unlike denominators and eventually multiplying and dividing fractions.
Common Misconception 1
A common misconception is that students think they need to add or subtract the denominators along with the numerators. This is incorrect because the denominator represents the whole, which does not change.
Intervention 1
Use visual fraction models to demonstrate that the whole remains the same, and only the parts (numerators) are added or subtracted.
Common Misconception 2
Another misconception is that students believe they must convert fractions to decimals to perform addition or subtraction. This is incorrect because fractions can be directly added or subtracted when they have like denominators.
Intervention 2
Provide practice problems focusing on adding and subtracting fractions without converting to decimals, using visual fraction models and equations.
Prerequisite Knowledge
Students should understand the concept of fractions as parts of a whole and be able to identify and write fractions. They should also be familiar with basic addition and subtraction.
Subsequent Knowledge
Students will develop the ability to add and subtract fractions with unlike denominators and will eventually learn to multiply and divide fractions.
Instructional Activities
- Use fraction strips to visually add and subtract fractions.
- Solve word problems involving fractions using visual models and equations.
- Create a class project where students measure and combine fractional lengths of different materials.
- Play fraction games that involve adding and subtracting fractions with like denominators.
