Step 1: Find a common denominator Scale up fractions in order for them to be out of the same number of parts. You need to find the least common multiple. Example: 1/3 + 5/8 Start by skip counting with the larger of the two numbers, in this case 8. 8, 16, 24, 32, 40 Stop at the first number that 3 will go into evenly, 24

Finding a common denominator Another way to find a common denominator is to multiply the denominators, but that does not always give you the least common multiple and will in the end require more reducing of the answer = 1(8) + 5(3)= = 3 83 (8) 8 (3)2424 Remember whatever you multiply the denominator by, you must also do to the numerator.

Step 2: Add or Subtract Once you’ve found a common denominator, simply add the numerators and keep the denominator the same =

More Practice Now try on your own: 1. 6/7 – 2/3 = 2. 1/8 + 5/6 =

Adding/ Subtracting Mixed Numbers Find a common denominator. 2 2/3 2 10/ / /15 Convert the mixed numbers to improper fractions 2 10/15 = (30/15) + (10/15) = 40/15

Adding/ Subtracting Mixed Numbers To convert to improper fractions, multiply the denominator by the whole number and add this to the numerator. Now place this number as the numerator over the denominator. 40/ /15 112/15 Now add the numerators, leave the denominators the same.

Adding/ Subtracting Mixed Numbers Change the improper fraction, back to a mixed number. 112/15 Ask yourself how many times does 15 go into 112 evenly? 15 x 7 = 105 Subtract 105 from = 7 15 goes into times evenly, with 7/15 as a remainder. 112/15 = 7 7/15