1. Fractions and Decimals
Lesson 10
Fractions and Decimals
Adding and Subtracting Mixed Numbers

2. Warm-up Find the value of 3 × 4 + 1. Find the value of 5 × 3 + 3.
Rewrite as an improper fraction.

3. Adding and Subtracting Mixed Numbers
Target:
Find sums and differences of expressions
that include mixed numbers.

6. Adding or Subtracting Mixed Numbers Using Improper Fractions
Write the mixed numbers as improper fractions.
If the denominators are different, rewrite the fractions using the least common denominator (LCD).
Add or subtract the numerators.
Write the sum or difference over the common denominator.
Simplify the fraction.

7. Example 1 Find the value of . Change to improper fractions.
Rewrite fractions with the least common denominator, 12.
Add the numerators.
Write as a mixed number.

8. Example 2 Seth ran a mile around the track. It took him minutes
to run a mile. His friend, Tremaine, also ran a mile on the
track. It took Tremaine minutes to run the mile. How
much faster did Seth run than Tremaine?
Write the problem.
Write as improper fractions.
The LCD is 6. Rewrite fractions
with the LCD.
Subtract the numerators.
Simplify.
Seth ran the mile minute faster than Tremaine.

9. Exit Problems Find the value of .
Jacob collected bags of aluminum cans to recycle on Monday. He collected bags of aluminum cans to recycle on Tuesday. How many bags did he collect in the two days?
Carmen bought 10 pounds of flour. She used pounds of flour for baking one week. How many pounds of flour did she have left?

10. Communication Prompt
What is the process for adding ?