Adding Fractions with Uncommon Denominators

What must fractions have before being added

The same denominator

What does LCM stand for

Least Common Multiple

What is the LCM

The smallest number that two denominators share

Step 1 for adding fractions with uncommon denominators

Find the LCM of the denominators

Step 2 for adding fractions with uncommon denominators

Rewrite each fraction with the LCM as the denominator

Step 3 for adding fractions with uncommon denominators

Add the numerators

Step 4 for adding fractions with uncommon denominators

Keep the denominator the same

Step 5 for adding fractions with uncommon denominators

Simplify if needed

Example solve 1/6 + 7/15

LCM is 30 rewrite as 5/30 and 14/30 add to get 19/30

Why do we multiply numerator and denominator by the same number

To make equivalent fractions without changing the value

When adding fractions what stays the same

The denominator

Property name for fractions must be rewritten first

Need for Common Denominators

Property name for only top numbers are added

Addition of Numerators

Property name for denominator stays the same

Identity of Denominator

Property name for fractions as parts of a whole

Part to Whole

Property name for order does not matter

Commutative Property

Property name for grouping does not matter when adding more than two

Associative Property