Holt CA Course Multiplying Fractions and Mixed Numbers NS2.1 Solve problems involving addition, subtraction, multiplication, and division of positive fractions and explain why a particular operation was used for a given situation. Also covered: NS2.4, NS2.2 California Standards

Holt CA Course Multiplying Fractions and Mixed Numbers Recall that multiplication can be written as repeated addition. For example, 3  5 = = 15. You can use repeated addition to multiply a whole number by a fraction.

Holt CA Course Multiplying Fractions and Mixed Numbers Example 1: Transportation Application In 2001, the car toll on the George Washington Bridge was $6.00. In 1995 the toll was 2 3 of that toll. What was the toll in 1995?  = = 12 3 = 4 1 = $4.00 The George Washington Bridge toll for a car was $4.00 in Think: How much is of 6? Use multiplication to find a fraction of a number. 2 3 Write the fraction as a decimal. Simplify

Holt CA Course Multiplying Fractions and Mixed Numbers

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Example 2A: Multiplying Fractions 12  = 12 1  3 4 Write 12 as a fraction. = 12  3 1  Divide a numerator and denominator by their GCD, = = 9 Multiply numerators. Multiply denominators. Simplify. Use the GCD of a numerator and denominator to simplify before multiplying. Remember!

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Additional Example 2B: Multiplying Fractions Multiply numerators. Multiply denominators.   = 3 5  1 4  = 3 20

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Additional Example 2C: Multiplying Fractions  8 = Divide a numerator and denominator by their GCD, 3. Multiply numerators. Multiply denominators =   3 8 

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out! Example 2A 16  = 16 1  1 4 Write 16 as a fraction. = 16  1 1  Divide a numerator and denominator by their GCD, = = 4 Multiply numerators. Multiply denominators.

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out! Example 2C  9 = Divide a numerator and denominator by their GCD, 6. Multiply numerators. Multiply denominators =   6 9 

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Example 3A: Multiplying Mixed Numbers Write the mixed number as an improper fraction. Divide a numerator and denominator by their GCD, 5. Multiply numerators. Multiply denominators  = 2 5  5 3 = 2 5   = 2 3

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Example 3B: Multiplying Mixed Numbers Write mixed numbers as improper fractions. Divide numerators and denominators by their GCDs, 5 and   1 7 = 21 5  15 7 = 5  = 9 1 or 9 Multiply numerators. Multiply denominators. 2

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Additional Example 3C: Multiplying Mixed Numbers Multiply numerators. Multiply denominators. 2 3   = 20 3   22 5 = 4 1 Write mixed numbers as improper fractions. Divide a numerator and denominator by their GCD, 5. 3 = 88 or

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out! Example 3B Write mixed numbers as improper fractions. Divide a numerator and denominator by their GCD,   1 = 18 5  4 3 = 5  Multiply numerators. Multiply denominators. = 24 5 or 4 4 5

Holt CA Course Multiplying Fractions and Mixed Numbers In 2002, the fee to park in a parking garage was $4. In 2000 the fee was of the fee in What was the fee in 2000? Check It Out! Example  = = 12 4 = 3 1 = $3.00 The fee to park in the parking garage was $3.00 in

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out! Example 2  8 Multiply numerators. Multiply denominators  3 7 = 3 7  1 8  = 3 56

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Check It Out! Example 3 Write the mixed number as an improper fraction. Divide a numerator and denominator by the GCD, 3. Multiply numerators. Multiply denominators  = 3 5  7 3 = 3 5   = or

Holt CA Course Multiplying Fractions and Mixed Numbers Multiply. Write the answer in simplest form. Multiply numerators. Multiply denominators. 1 6   = 19 6   4 3 = 3 2 Write mixed numbers as improper fractions. Divide a numerator and denominator by their GCD, 2. 9 = 38 or Check It Out! Example 3C