MATH LESSONS WITH FUGO

SUBTRACTING FRACTIONS

@VerySleepyLoner

Easy ways to begin subtracting fractions:

Step 1. Make sure the bottom numbers (the denominators) are the same

Step 2. Subtract the top numbers (the numerators). Put the answer over the same denominator.

Step 3. Simplify the fraction (if needed).

Keeping these in mind, let's practice.

EXAMPLE 1.

7/5 - 3/5

First things first. What do we notice here? They both have the same denominator.
So really, all we do here is:
                                     7 - 3
Which equals 4. Pretty easy right? Now just add the 5 into the denominator to make it 4/5.

Now just do the same to all of the equations below.

Practice

EXAMPLE 2

So...What would we do if the denominators are different? Well, looking back at step 2, we have to subtract the top numbers.

So what does that look like?

Let's take the fractions

1/2 - 1/6

To make the bottom numbers the same, multiply the top and bottom of the first fraction (1/2) by 3 like this:

Reason why: We cant subtract fractions just like that, so we have to change the smaller number of the denominators to match the other because we cant multiply 6 and get 2.
We know 2×3 equal 6, which is why we multiplied by 3.