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

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

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

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.

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.

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.

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?

Communication Prompt What is the process for adding ?