Fractions Vocabulary Numerator: The top number in a fraction. The number of parts. Denominator: The bottom number in a fraction. How many equal parts something is divided into. 2 Numerator 3 Denominator Vocabulary Least Common Multiple (LCM): The smallest multiple shared between a group of numbers Least Common Denominator (LCD): The smallest multiple shared between a group of denominators Finding the Least common multiple or denominator 1. List the multiples of your first number a. EXAMPLE 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 2. List the multiples of your second number a. EXAMPLE 7: 7, 14, 21, 28 3. Find the SMALLEST number that is shared Find the Least Common Multiple. Type the Answer in the center column. Number 1 Least Common Multiple Number 2 2 3 7 56 8 5 44 14 20 22 13 31 Adding Fractions If the denominators are the same. Add the numerators. Simplify if needed. 2 3 5 8 8 8 Adding Fractions with different denominators Step 1: Find the LCD Problem 2 1 8 3 Multiples of 8 8, 16, 24, 32, Multiples of 3 3, 6, 9, 12, 15, 18, 21, 24 Step 2: Multiply the Fractions 2 3 8 3 24 6 LCD is 24 Step 3: Add the new fractions 6 8 14 24 24 24 Step 4: Simplify 1 8 8 14 2 7 3 8 24 24 2 12 PROOF 2 8 6 24 8 24 1 3 Subtracting Fractions Works the same as adding, just subtract If the denominators are equal then subtract the numerators If the denominators are different then find the LCD, multiply the numerator and denominator, then subtract Simplify if needed Guided practice 2 1 6 2 3 5 8 8 3 6 7 3 12 12 8 6