Comparing Fractions By: Greg Stark EC&I 831

Why compare fractions? To determine which fraction represents a larger value Fractions with the same denominator are called like fractions and can be compared by their numerators The larger fraction has the biggest numerator >

What if the they are unlike fractions? It can be difficult to determine which fraction is larger by looking at a diagram

What if they are unlike fractions? To determine which fraction represents a larger value with unlike fractions: 1.Multiply each denominator by the opposite numerator Important: always cross multiply from denominator (bottom) to opposing numerator (top) or this method will not work < 2.Write the product (answer) beside the numerator 3.The side with the largest product, is the larger fraction 7 X 3 = 21 5 X 4 = 20

What if there are more than two fractions? This method will still work You must compare each fraction to the others to ensure you have them in the correct order – a time consuming process Converting all of the fractions to like terms is another method which may make this easier This method is discussed in the Adding Unlike Fractions presentation

Review: to compare fractions 1.For like fractions, the larger fraction is the one with the larger numerator 2.For unlike fractions, multiply opposing denominators (bottom) to numerators (top) – The side with the largest product is the larger fraction