#### A quick and easy way to declare a common denominator is multiply the denominators together. I always start with this and then see if I can reduce that value to find an easier value to work with. You will be giving a bunch of addition sentences to complete after you make that initial denominator match. At that point, all you need to do is find the sum of the numerators. When it comes to fractions this is the basic step towards working with more complex fractional operations (such as multiplication and division).

What are unlike fractions, and how do you find their sum?
Mathematic number systems are mainly divided into two portions, including whole numbers and fractions. Whole numbers are those that do not contain decimal numbers or fractions. Fractions, on the other hand, represent the part of the whole number. While 0 and 1 are whole numbers, the numbers between 0 and 1, including 0.1, 0.2,0.003, are decimal numbers that can be written as a fraction.
Now, you may come across two types of fractions; those with the same denominators, that we know as like-fractions, and those with different denominators, that we know as unlike-fractions.
While adding like-fractions is simple and straightforward, you have to bring the concept of LCM, Least Common Factor into consideration when summing two unlike-fractions. You have to make the denominators the same if you want to sum these fractions.
Consider an example where you have to add two fractions; ½ + ⅖
To solve this, you need to look for the least common factor for the denominators, and in this case, it is 10. Now what you have to do is that multiply both the numerator and denominator with a number that brings 10 in the denominator;
(1 × 5) / (2 × 5)= 5/ 10
(2 × 2) / (5 × 2) = 4/10
Now that we have the same denominators and have converted the unlike-fractions into like fractions, we can take 1/10 common and add 5 and 4.
1/10 (5 + 4) = 1/10 (9) = 9/10 These worksheets explain how to add fractions with like and unlike denominators. A series of lessons and guided practice sheets can be worked on by themselves.