1 / 24

11/30/09 Multiply & Divide Fractions #1

11/30/09 Multiply & Divide Fractions #1 . LT: I will learn to multiply and divide mixed numbers and fractions. Fraction, Decimal, Percent Wheels Circle all fractions that are in lowest terms. Review the conversions & decorate your wheel. Today’s Plan:

tashya-mckenzie
Télécharger la présentation

11/30/09 Multiply & Divide Fractions #1

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 11/30/09 Multiply & Divide Fractions #1 LT: I will learn to multiply and divide mixed numbers and fractions. Fraction, Decimal, Percent Wheels • Circle all fractions that are in lowest terms. • Review the conversions & decorate your wheel. Today’s Plan: -Fraction, Decimal, Percent Wheel game -Lesson -Assignment Learning Target: I will learn to multiply and divide mixed numbers and fractions.

  2. 11/30/09 Multiply & Divide Fractions #1 LT: I will learn to multiply and divide mixed numbers and fractions. Fraction, Decimal, Percent Wheels Today’s Plan: -Fraction, Decimal, Percent Wheel game -Lesson -Assignment Learning Target: I will learn to multiply and divide mixed numbers and fractions.

  3. 11/30/09 Multiply & Divide Fractions #1 LT: I will learn to multiply and divide mixed numbers and fractions. Warm-up Katie made a bookshelf that is 5 feet long. The first 6 books she put on it took up 8 inches of shelf space. About how many books should fit on the shelf? 45 books Today’s Plan: -Fraction, Decimal, Percent Wheel game -Lesson -Assignment Learning Target: I will learn to multiply and divide mixed numbers and fractions.

  4. RULES FOR MULTIPLYING TWO RATIONAL NUMBERS If the signs of the factors are the same, the product is positive. (+) • (+) = (+) (–) • (–) = (+) If the signs of the factors are different, the product is negative. (+)•(–)=(–) (–)•(+)=(–)

  5. –8 • 6 7 –48 7 6 7 –6 Multiply. Write the answer in simplest form. 6 7 A. –8 Multiply Simplify

  6. 2 5 9(5) + 2 5 47 5 47 5 9 = 4 = 188 5 3 5 37 Try This: Example 1B Multiply. Write the answer in simplest form. 2 5 9 4 B. Multiply Simplify

  7. 1(6) 8(7) = 3 1(6) 8(7) = 4 3 28 = Additional Example 2A: Multiplying Fractions Multiply. Write the answer in simplest form. 6 7 1 8 A. Multiply numerators. Multiply denominators. Look for common factors: 2. Simplest form

  8. –2(9) 3(2) = –1 –2(9) 3(2) 3 = 1 1 –3 = Additional Example 2B: Multiplying Fractions Multiply. Write the answer in simplest form. 2 3 9 2 B. – Multiply numerators. Multiply denominators. Look for common factors: 2, 3. Simplest form

  9. 3(5) 5(8) = 1 3(5) 5(8) = 1 3 8 = Try This: Example 2A Multiply. Write the answer in simplest form. 5 8 3 5 A. Multiply numerators. Multiply denominators. Look for common factors: 5. Simplest form

  10. –7(4) 8(7) = –1 –7(4) 8(7) 1 = 1 2 1 2 = – Try This: Example 2B Multiply. Write the answer in simplest form. 4 7 7 8 B. – Multiply numerators. Multiply denominators. Look for common factors: 4, 7. Simplest form

  11. 13(7) 5(9) 91 45 1 45 = or 2 Try This: Example 2C Multiply. Write the answer in simplest form. 7 9 3 5 C. 2 Write as an improper fraction. 13 7 5 9 Multiply numerators. Multiply denominators. 91 ÷ 45 = 2 R 1

  12. 1 8 Evaluate –3 x for the value of x. 18 18 –3 x –3 (5) –25 8 = = (5) –125 8 = 5 8 = –15 Additional Example 4A: Evaluating Expressions with Rational Numbers A. x = 5 Substitute 5 for x. Write as an improper fraction. –125 ÷ 8 = –15 R5

  13. 1 8 Evaluate –3 x for the value of x. 18 –3 x 18 2 7 27 = –3 Substitute for x. 27 –25 8 = –25 • 2 = 8 • 7 25 28 = – Additional Example 4B: Evaluating Expressions with Rational Numbers Continued 2 B. x = 7 Write as an improper fraction. 1 Look for common factors: 2. 4

  14. 3 5 Evaluate –5 y for the value of y. 35 –5 y 6 7 Substitute for x. 67 35 = –5 67 –28 5 = –28 • 6 = 5 • 7 24 5 45 = – , or – 4 Try This: Example 4A 67 A. y = Write as an improper fraction. –4 Look for common factors: 7. 1

  15. 3 5 Evaluate –5 y for the value of y. 35 –5 y 35 = –5 (3) –28 5 (3) = –84 5 = 4 5 = –16 Try This: Example 4B B. y = 3 Substitute 3 for y. Write as an improper fraction. –84 ÷ 5 = –16 R4

  16. A number and its reciprocalhave a product of 1. To find the reciprocal of a fraction, exchange the numerator and the denominator. Remember that an integer can be written as a fraction with a denominator of 1.

  17. 2 5 2 5 1 3 1 3 2 15 2 15 ÷ = = 5 2 1 3 2 15 2•515 •2 Multiplication and division are inverse operations. They undo each other. Notice that multiplying by the reciprocal gives the same result as dividing. = =

  18. 1 2 2 1 5 11 5 11 = ÷ • 2 1 5 11 = • 10 11 = Additional Example 1A: Dividing Fractions Divide. Write the answer in simplest form. 1 2 5 11 A. ÷ Multiply by the reciprocal. No common factors. Simplest form

  19. 2 1 3 8 19 8 = ÷ ÷ 2 2 19 8 1 2 = 19 • 1 = 8 • 2 3 16 19 16 1 = = Additional Example 1B: Dividing Fractions Divide. Write the answer in simplest form. 3 8 B. 2 2 ÷ Write as an improper fraction. Multiply by the reciprocal. No common factors 19 ÷ 16 = 1 R 3

  20. 3 4 7 15 4 3 7 15 ÷ = • 7 • 4 = 28 45 15 • 3 = Try This: Example1A Divide. Write the answer in simplest form. 3 4 7 15 A. ÷ Multiply by the reciprocal. No common factors. Simplest form

  21. 22 5 3 1 2 5 4 ÷ 3 ÷ = 22 5 1 3 = 22 • 1 = 5 • 3 22 15 7 15 1 = or Try This: Example1B Divide. Write the answer in simplest form. 2 5 4 3 B. ÷ Write as an improper fraction. Multiply by the reciprocal. No common factors. 22 ÷ 15 = 1 R 7

  22. 5 1 5 4 4 5 • = 1 4 254 = 5 • 5 6 = = 1 • 4 Additional Example 3B: Evaluating Expressions with Fractions and Decimals Evaluate the expression for the given value of the variable. 4 5 B. k ÷ for k = 5 5÷

  23. 9 1 7 4 4 7 = ÷ 9 9 • 7 = 1 • 4 3 4 = 15 Try This: Example 3B Evaluate the expression for the given value of the variable. 4 7 B. u ÷ , for u = 9 Write as in improper fraction and multiply by the reciprocal. No common factors. 63 ÷ 4 = 15 R 3

  24. Assignment Pg 124 5-12

More Related