Concept

● Like fractions are fractions with the same denominator. 
● Unlike fractions are fractions with different denominators. 
● A fraction is said to be in simplest form if its numerator and denominator have no common factors other than 1.
● Improper fractions should be written as mixed numbers
● Words that mean to add are: sum, plus, increase, total, altogether, combined, or
● Words that mean to subtract are: minus, less, difference, how much more

Rule

To add or subtract fractions:
1. Create equivalent fractions, so denominators are like if needed.
2. Add or subtract the numerators. The denominator stays the same.
3. Write the answer as a whole number, simplified fraction, or mixed number

Example

Sarah bought 79 of a yard of fabric and her mother bought 56 a yard of fabric. How many yards of fabric did they buy altogether?

Solution

Add 79 + 56

Create equivalent fractions
The lowest common denominator of 9 and 6 is 18. 

Add the numerators, the denominator stays the same
1418+1518 = 2918

Write the answer as a whole number, simplified fraction or mixed number.
2918 = 11118

Answer: 11118 yards

Pre-requisite Skills

Equivalent Fractions (5.10.5)

Simplifying fractions (5.10.6)

Convert improper fractions mixed numbers (6.4.5)

Add Fractions with Like Denominators (6.7.2)

Add Fractions with Unlike Denominators (6.7.3)