Lesson 5 Fractions and Decimals Ordering and Comparing

Lesson 5 Fractions and Decimals Ordering and Comparing Fractions

Warm-Up 1. What do the symbols < and > mean? 2. Find the LCD for 3. Find the LCD for . .

Ordering and Comparing Fractions Target: Compare fractions with like and unlike denominators to find the smallest or largest fraction.

Compare and Order Fractions with Unlike Denominators 1. Find the least common denominator (LCD) for the fractions in the set. 2. Change each fraction to an equivalent fraction using the LCD. 3. Compare the numerators.

Example 1 In a recent survey, three-fifths of people liked peanut butter and jam. One-third liked grilled cheese sandwiches. Compare three-fifths and one-third to find which food was most popular. � � 3: The denominators are 3 and 5. 3, 6, 9, 12, 15, … � 5: 5, 10, 15, 20, 25, … � The LCM = 15, so the LCD = 15.

Example 1 (continued) � Make equivalent fractions with denominators of 15. � Compare the numerators. Nine is larger than 5. If � The . group that liked peanut butter and jam sandwiches was larger.

Example 2 � List the following fractions from least to greatest: The denominators are 2, 6 and 3. � 2: 2, 4, 6, 8, 10 � 6: 6, 12, 18, 24 � 3: 3, 6, 9, 12, 15 � The LCM = 6, so the LCD = 6. � Make equivalent fractions. � � Compare numerators. � Substitute the original fractions and order.

Example 3 Find a fraction between . Write in simplest form. � The denominators are 6 and 2. � 6: 6, 12, 18, … � 2: 2, 4, 6, 8, … � Make equivalent fractions. � Compare � the fractions. A fraction that would be between is .

Exit Problems 1. Compare each pair of fractions. Replace the <, > or = to make a true sentence. with 2. Write the fractions in order from least to greatest.

Communication Prompt What is the process for ordering three fractions with three different denominators?