Lesson 4: Solve word problems involving addition and subtraction of fractions.

Property

The RDW (Read, Draw, Write) process is a strategy for solving word problems:

1. Read the problem to understand the question and identify the knowns and unknowns.
2. Draw a model, such as a tape diagram, to visualize the relationship between the fractions.
3. Write a number sentence (equation) to solve the problem and a word sentence to state the final answer.

Examples

Property

To add fractions with like denominators in a word problem, add the numerators and keep the denominator the same: $\frac{a}{c} + \frac{b}{c} = \frac{a+b}{c}$.
If the resulting sum is an improper fraction ($a+b \geq c$), convert it to a mixed number to state the final answer.

Examples