 # Adding Fractions with Unlike Denominators

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Videos, solutions, examples and songs to help Grade 4 students learn how to add fractions with unlike denominators.

Addition of fractions with unlike denominators
Examples:
2. The Pacific Ocean covers 1/3 of the Earth's surface. The Atlantic Ocean covers 1/5 of the Earth's surface. What fraction of the Earth's surface is covered by both the Atlantic and Pacific Ocean?
How to add fractions with unlike denominators?
Step 1: Line the fractions up vertically.
Step 2: Find the LCD (least common denominator) which is the LCM (least common multiple) of all the denominators.
Step 3: Write the fractions with the same denominator which will be the LCD.
Step 4: Add the numerators of the new fractions.
Step 5: Simplify the fractions when necessary.
Example:
1/4 + 1/3
Adding 3 Fractions with Uncommon Denominators
Step 1: Change all fractions to have a common denominator
Step 2: Add the numerators while keeping the same denominator.
Step 3: Reduce when possible.
Example:
1/12 + 1/8 + 10/16

Adding Fractions Song for Kids | Finding the Least Common Denominator
Lyrics:
Find the least common multiple - that's the first action.
Next is finding equivalent fractions.
Then do the addition or subtraction.
Simplify is the automatic reaction.
Visually adding fractions with unlike denominators
Example:
5/6 + 1/4
Example:
3/5 + 1/6
12/27 + 2/9

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