1. Adding and Subtracting with Like Denominators 4-8
Warm Up
Problem of the Day
Lesson Presentation
Course 1

2. 4-8 Adding and Subtracting with Like Denominators Warm Up
Course 1
4-8
Adding and Subtracting with Like Denominators
Warm Up
Write each mixed number as an improper fraction. 1 3 __ 19 3 __ 1 5 __ 11 5 __ 2 7 __ 23 7 __ 1 2 __ 17 2 __ 4 5 __ 49 5 __ 8 11 __ 52 11 __

3. 4-8 Adding and Subtracting with Like Denominators Problem of the Day
Course 1
4-8
Adding and Subtracting with Like Denominators
Problem of the Day
Marge has six coins that total $1.15. She cannot make change for $1.00, a half-dollar, a quarter, a dime, or a nickel. What coins does she have?
half dollar, quarter, 4 dimes

4. 4-8 Learn to add and subtract fractions with like denominators.
Course 1
4-8
Adding and Subtracting with Like Denominators
Learn to add and subtract fractions with like denominators.

5. Additional Example 1: Application
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4-8
Adding and Subtracting with Like Denominators
Additional Example 1: Application 1 4 __
Snow was falling at a rate of inch per hour. How
much snow fell after two hours? Write your answer in simplest form. 1 4 __ 1 4 __ + 1 4 __ 1 4 __ 2 4 __
Add the numerators. Keep the same denominator + = 1 2 __ =
Write your answer in simplest terms. + = 1 2 __
After 2 hours inch of snow fell

6. 4-8 Adding and Subtracting with Like Denominators Try This: Example 1
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4-8
Adding and Subtracting with Like Denominators
Try This: Example 1 1 8 __
Rain was falling at a rate of inch per hour. How
much rain fell after two hours? Write your answer in simplest form. 1 8 __ 1 8 __ + 1 8 __ 1 8 __ 2 8 __
Add the numerators. Keep the same denominator. + = 1 4 __ =
Write your answer in simplest terms. + = 1 8 __
After 2 hours inch of rain fell.

7. Additional Example 2A: Subtracting Like Fractions and Mixed Numbers
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4-8
Adding and Subtracting with Like Denominators
Additional Example 2A: Subtracting Like Fractions and Mixed Numbers
Subtract. Write the answer in simplest form.
A. 1 – 3 5 __
To get a common denominator, rewrite 1 as a fraction with a denominator of 5. 5 __ 3 5 __ 2 5 __ – =
Subtract the numerators. Keep the same denominator. ― =

8. Additional Example 2B: Subtracting Like Fractions and Mixed Numbers
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4-8
Adding and Subtracting with Like Denominators
Additional Example 2B: Subtracting Like Fractions and Mixed Numbers
Subtract. Write the answer in simplest form.
B – 2 5 12 __ 1 12 __ 5 12 __ 1 12 __ 5 – 2
Subtract the fractions. 4 12 __ 3
Then subtract the whole numbers. 1 3 __ 3
Write your answer in simplest form. - =

9. 4-8 Adding and Subtracting with Like Denominators Try This: Example 2A
Course 1
4-8
Adding and Subtracting with Like Denominators
Try This: Example 2A
Subtract. Write the answer in simplest form.
A. 1 – 2 6 __
To get a common denominator, rewrite 1 as a fraction with a denominator of 6. 6 __ 2 6 __ 4 6 __ – =
Subtract the numerators. Keep the same denominator. – =

10. 4-8 Adding and Subtracting with Like Denominators Try This: Example 2B
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4-8
Adding and Subtracting with Like Denominators
Try This: Example 2B
Subtract. Write the answer in simplest form.
B – 2 7 12 __ 4 12 __ 7 12 __ 4 12 __ 4 – 2
Subtract the fractions. 3 12 __ 2
Then subtract the whole numbers. 1 4 __ 2
Write your answer in simplest form. - =

11. Additional Example 3A: Evaluating Expressions with Fractions
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4-8
Adding and Subtracting with Like Denominators
Additional Example 3A: Evaluating Expressions with Fractions 2 9 __
Evaluate the expression for x = . Write each answer in simplest form. 5 9 __ A. – x 5 9 __ – x
Write the expression. 2 9 __ 5 9 __ 2 9 __ 3 9 __
Substitute for x and subtract the
numerators. Keep the same denominator. – = 1 3 __ =
Write your answer in simplest form.

12. Additional Example 3B: Evaluating Expressions with Fractions
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4-8
Adding and Subtracting with Like Denominators
Additional Example 3B: Evaluating Expressions with Fractions 2 9 __
Evaluate the expression for x = . Write each answer in simplest form. 4 9 __ B. x + 2 4 9 __ x + 2
Write the expression. 2 9 __ 2 9 __ 4 9 __ 6 9 __
Substitute for x. Add the
fractions. Then add the whole numbers. + 2 = 2 2 3 __ 8 3 __
Write your answer in simplest form. = 2
, or

13. Additional Example 3C: Evaluating Expressions with Fractions
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4-8
Adding and Subtracting with Like Denominators
Additional Example 3C: Evaluating Expressions with Fractions 2 9 __
Evaluate the expression for x = . Write each answer in simplest form. 8 9 __ C. x + 8 9 __ x +
Write the expression. 2 9 __ 2 9 __ 8 9 __ 10 9 __ 1 9 __
Substitute for x and subtract
the numerators. Keep the same denominator. + =
, or 1

14. 4-8 Adding and Subtracting with Like Denominators Try This: Example 3A
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4-8
Adding and Subtracting with Like Denominators
Try This: Example 3A
Evaluate the expression for x = . Write each answer in simplest form. 2 6 __ 4 6 __ A. – x 4 6 __ – x
Write the expression. 2 6 __ 4 6 __ 2 6 __ 2 6 __ – =
Substitute for x and subtract the
numerators. Keep the same denominator. 1 3 __ =
Write your answer in simplest form.

15. 4-8 Adding and Subtracting with Like Denominators Try This: Example 3B
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4-8
Adding and Subtracting with Like Denominators
Try This: Example 3B
Evaluate the expression for x = . Write each answer in simplest form. 2 6 __ 1 6 __ B. x + 3 1 6 __ x + 3
Write the expression. 2 6 __ 2 6 __ 1 6 __ 3 6 __
Substitute for x and subtract
the numerators. Keep the same denominator. + 3 = 3 1 2 __
Write your answer in simplest form. = 3

16. 4-8 Adding and Subtracting with Like Denominators Try This: Example 3C
Course 1
4-8
Adding and Subtracting with Like Denominators
Try This: Example 3C
Evaluate the expression for x = . Write each answer in simplest form. 2 6 __ 5 6 __ C. x + 5 6 __ x +
Write the expression. 2 6 __ 2 6 __ 5 6 __ 7 6 __ 1 6 __
Substitute for x and subtract
the numerators. Keep the same denominator. + =
, or 1

17. 4-8 Adding and Subtracting with Like Denominators Lesson Quiz
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4-8
Adding and Subtracting with Like Denominators
Lesson Quiz
Add or subtract. Write each answer in simplest form.
1. 1 – –
4. Evaluate – x for x = . 9 11 __ 2 11 __ 8 9 __ 1 9 __ 3 10 __ 1 10 __ 2 5 __ 6 16 21
___ 6 21 __ 10 21 __ 3 4 __
5. Weston walks of a mile every day. How far
will he have walked in 4 days?
3 miles