Comparing fractions Adding and Subtracting Fractions Factor A
Comparing fractions Adding and Subtracting Fractions
Factor • A number that divides evenly into another. Factors of 24 are 1, 2, 3, 4, 6, 8, 12 and 24. n
What are the factors of 9? n Factors of 9 are 1, 3 and 9.
What are the factors of 10? Factors of 10 are 1, 2, 5 and 10. n
Common Factor When two numbers have the same factor it is called a common factor. n A common factor of 12 and 6 is 3. n
Name a Common Factor of 9 and 27? 1, 3, 9
Name a Common Factor of 15 and 30? 1, 3, 5, 15
Name a Common Factor of 12 and 48? 1, 2, 3, 4, 6, 12
Name a Common Factor of 9 and 21? 1, 3, 9,
Name a Common Factor of 10 and 25? 1, 5, 10
Name a Common Factor of 3 and 4? 1
Greatest Common Factor • The greatest common factor is the largest factor between two numbers. 12 = 1, 2, 3, 4, 6, 12 18 = 1, 2, 3, 6, 9, 18
What is the Greatest Common Factor? 8 = 1, 2, 4, 8 12 = 1, 2, 3, 4, 6, 12
What is the Greatest Common Factor? 8 = 1, 2, 4, 8 14 = 1, 2, 7, 14
What is the Greatest Common Factor? 6 = 1, 2, 3, 6 18 = 1, 2, 3, 6, 9, 15
How to Find the Simplest Form of a Fraction • Find the greatest common factor of the numerator and the denominator and divide both the numerator and the denominator by that number. 12 6 2 ÷ = 18 6 3
Simplify or Reduce This Fraction 9 3 3 ÷ = 21 3 7
Simplify or Reduce This Fraction 12 4 3 ÷ = 20 4 5
Simplify or Reduce This Fraction 10 5 2 ÷ = 15 5 3
Simplify or Reduce This Fraction 10 2 5 ÷ = 16 2 8
Simplify or Reduce This Fraction 12 4 3 ÷ = 16 4 4
Simplify or Reduce This Fraction 3 3 1 ÷ = 12 3 4
Comparing fractions Step 1: Find a common denominator Step 2: Make equivalent fractions with the new denominator Step 3: Compare the numerators (when you have more than 2 fractions) Short cut: Cross multiply (Multiply each fraction by the other fraction’s denominator.
Compare: 3/5 and 7/9 • 5 x 9 = 45 and 3 X 9= 27 So 3/5= 27/45 • 9 x 5+ 45 and 7 x 5=35 So 7/9=35/45 27 ‹ 35 SO 3/5 ‹ 7/9 Short Cut: 3/5 7/9 3 x 9=27 and 7 x 5=35 3/5 ‹ 7/9 27 ‹ 35
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