Adding and Subtracting Fractions

After all those short lessons and exercises about decimals, it is now time for us to take a dip into fractions. Just like decimals, fractions are also easy, as long as you know the basics. In this entry, we will learn how to add and subtract fractions, the EASY WAY. Let us first begin with an example of ADDING LIKE FRACTIONS;

³⁄₈ + ²⁄₈

As you can see in the example above, both the fractions have the same bottom number. The trick is, we can just add them by adding the top numbers and then keeping the same bottom number (denominator). So 3 + 2 = 5 and then just copy the bottom number like so;

³⁄₈ + ²⁄₈ = ⁵⁄₈

This method also applies to subtracting. Here’s a basic example of subtracting fractions that have the same bottom number. Just subtract the top numbers, then copy the denominator. Easy and simple.

⁷⁄₉ – ⁴⁄₉ = ³⁄₉

 

So there it is, when adding and subtracting LIKE FRACTIONS, just add or subtract the top numbers then just copy the denominator or the bottom number. There’s really no complicated process, but how about if the two fractions that needed to be added or subtracted are different? Have a look at the example below;

¹⁄₄ + ²⁄₅

 

We are now dealing with fractions with unlike denominators so we cannot use our method of adding and subtracting like fractions. Some of you will say, “that’s easy, just find the least common denominators” and while that is the correct process, there’s a much simpler way to do it. Watch this video from techmath.

 

Pretty easy, right? Using that method we can now answer the example ¹⁄₄ + ²⁄₅.

 

The same method works for subtracting unlike fractions.

1. First, multiply the denominators of both fractions.

2. Then start at the first fraction’s numerator and multiply it by the second fraction’s denominator.

3. After that, multiply the second fraction’s numerator t0 the first fraction’s denominator.

4. Finally, subtract the two numerator products to get the difference.

5. In this case however, even though we already have an answer, it still can be converted to the lowest term. You do know how to simplify fractions to their lowest term, right?

6. So our final answer to the equation above is ¹⁄₆.

 

Adding and Subtracting Fractions Exercises

Since these equations are a bit easy, there will only be a handful of exercises below and no multiple choices. You should solve them regardless of their difficulty because these basic computations will help you pass the CSC examination easily. Write your answers in a sheet of paper and don’t forget to simplify the answer if needed.

 

1. ²⁄₆ + ³⁄₆ = ___?

2. ³⁄₇ + ¹⁄₇ = ___?

3. ²⁄₈ + ²⁄₈ = ___?

4. ⁶⁄₉ + ³⁄₉ = ___?

5. ²⁄₇ + ¹⁄₇ = ___?

6. ³⁄₅ – ²⁄₅ = ___?

7. ⁴⁄₇ – ¹⁄₇ = ___?

8. ⁸⁄₉ – ³⁄₉ = ___?

9. ³⁄₆ – ²⁄₆ = ___?

10. ⁵⁄₉ – ⁴⁄₉ = ___?

11. ²⁄₅ + ¹⁄₄ = ___?

12. ³⁄₄ + ²⁄₈ = ___?

13. ¹⁄₈ + ³⁄₇ = ___?

14. ⁴⁄₇ + ¹⁄₉ = ___?

15. ³⁄₉ + ³⁄₇ = ___?

16. ²⁄₃ – ³⁄₅ = ___?

17. ⁴⁄₆ – ²⁄₈ = ___?

18. ⁸⁄₁₀ – ¹⁄₉= ___?

19. ⁸⁄₉ – ⁷⁄₁₀ = ___?

20. ⁴⁄₇ – ⁴⁄₉ = ___?

Go ahead and click any of the sharing buttons below to see the answers to this CSC Reviewer Fraction questionnaire.

For more Math exercises to prepare you for the upcoming Civil Service Examination, check out this CSC Reviewer Numerical Reasoning tests.