LESSON 14 – ADDITION AND SUBTRACTION OF FRACTIONS WITH DIFFERENT DENOMINATORS.

Objective:

At the end of this lesson, students should be able to add and subtract fractions with different denominators.

METHOD 1
when adding or subtracting fractions that have different denominators, you need to follow a number of steps.

STEP 1: First check the denominators of the fractions you are working with to see   if you can change one to become equivalent to the other.

STEP 2: Re-write these fractions as their equivalent fractions so that they all have the same denominator.

STEP 3: You can then add or subtract the numerators accordingly and maintain the common denominator.

STEP 4: Simplify your answer to its simplest/lowest term.

We can only add or subtract fractions with the same denominator. We can also manipulate fractions with different denominators so that we get the same denominators. This makes addition and subtraction of fractions easier

METHOD 2

This method involves finding the Least Common Multiple or Denominator (LCM/ LCD).

STEP 1: Find the LCM/ LCD of the fractions.

STEP 2: Divide the LCM or LCD by each of the denominators and multiply their numerators by the quotient.

STEP 3: Add or subtract the numerators as required by the questions. Simplify where needed.