# Fractions

## Add and Subtract Fractions with Common Denominators


### Model Fraction Addition

How many quarters are pictured? One quarter plus  quarters equals  quarters.
Remember, quarters are really fractions of a dollar. Quarters are another way to say fourths. So the picture of the coins shows that
Let’s use fraction circles to model the same example, 
So again, we see that

### Add Fractions with a Common Denominator

 shows that to add the same-size pieces—meaning that the fractions have the same denominator—we just add the number of pieces.

### Model Fraction Subtraction

Subtracting two fractions with common denominators is much like adding fractions. Think of a pizza that was cut into  slices. Suppose five pieces are eaten for dinner. This means that, after dinner, there are seven pieces (or  of the pizza) left in the box. If Leonardo eats  of these remaining pieces (or  of the pizza), how much is left? There would be  pieces left (or  of the pizza).
Let’s use fraction circles to model the same example, 
Start with seven  pieces. Take away two  pieces. How many twelfths are left?
Again, we have five twelfths, 

### Subtract Fractions with a Common Denominator

We subtract fractions with a common denominator in much the same way as we add fractions with a common denominator.
Now lets do an example that involves both addition and subtraction.

### Key Concepts

1. Fraction Addition
2. Fraction Subtraction

### Practice Makes Perfect

Model Fraction Addition 
In the following exercises, use a model to add the fractions. Show a diagram to illustrate your model.
Add Fractions with a Common Denominator 
In the following exercises, find each sum.
Model Fraction Subtraction 
In the following exercises, use a model to subtract the fractions. Show a diagram to illustrate your model.
Subtract Fractions with a Common Denominator 
In the following exercises, find the difference.
Mixed Practice 
In the following exercises, perform the indicated operation and write your answers in simplified form.

### Everyday Math


### Writing Exercises


### Self Check

ⓐ After completing the exercises, use this checklist to evaluate your mastery of the objectives of this section.



ⓑ On a scale of 1–10, how would you rate your mastery of this section in light of your responses on the checklist? How can you improve this?
