Adding and Subtracting Unlike Fractions 5th Grade Math Worksheets

Definition:

Unlike Fractions are fractions with different denominators.

Summary:

MULTIPLES

• It is the result of multiplying numbers by another whole number. 
• It is possible that a number can be a multiple of two or more numbers. This is called common multiple.
• The smallest number that is common to two or more multiples is called least common multiple.
• Determining the correct least common multiple (LCM) is needed to get the least common denominators of two unlike fractions. 

GREATEST COMMON FACTORS

The greatest common factor, or GCF, is the greatest factor that divides two numbers. 

To find the GCF of two numbers:

• List the prime factors of each number.
• Multiply those factors both numbers have in common. If there are no common prime factors, the GCF is 1.

GCF is needed in simplifying fractions or expressing them in simplest form.

Example:

Multiples of 2	2	4	6	8	10	12
Multiples of 3	3	6	9	12	15	18

Since the multiples of 2 contains 6 and 12 and the multiples of 3 contains 6 and 12 as well, 6 and 12 are already considered common multiples. 6 is the smallest common multiple, it is call the least common multiple of 2 and 3. 

Find the GCF of 18 and 24.

The prime factors of 18 are 2 x 3 x 3.
The prime factors of 24 are 2 x 2 x 2 x 3
Notice that there is one 2 and one 3 in common.
Thus, the GCF of 18 and 24 is 2 x 3 = 6. 

Adding and Subtracting Unlike Fractions Worksheets

This is a fantastic bundle which includes everything you need to know about Adding and Subtracting Unlike Fractions across 15+ in-depth pages. These are ready-to-use Common core aligned Grade 5 Math worksheets.

Each ready to use worksheet collection includes 10 activities and an answer guide. Not teaching common core standards? Don’t worry! All our worksheets are completely editable so can be tailored for your curriculum and target audience.

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