Parts of a Whole

Adding fractions is like putting puzzle pieces together. If you have $\frac{1}{4}$ of a pizza and your friend gives you $\frac{2}{4}$ more, you just count how many fourths you have in total!


The Golden Rule

When the denominators (the bottom numbers) are the same, the "size" of the pieces doesn't change. You only change the top!

OperationRuleExample (LaTeX)
Addition Add the numerators. Keep the denominator the same. $\frac{2}{8} + \frac{3}{8} = \frac{5}{8}$
Subtraction Subtract the numerators. Keep the denominator the same. $\frac{7}{10} - \frac{4}{10} = \frac{3}{10}$
Wait! Never add the denominators! $\frac{1}{2} + \frac{1}{2}$ is not $\frac{2}{4}$. $\frac{1}{2} + \frac{1}{2} = \frac{2}{2} = 1$
Combine the parts:
1
4
+
2
4
=

Simplifying Fractions Video

Watch one more quick explanation to reinforce how the GCF makes simplification fast.


Simplifying Fractions

Shortcut: divide numerator and denominator by the greatest common factor (GCF) to write fractions in simplest form.


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Fraction Scientist!

You’ve mastered the art of combining, separating, and simplifying parts of a whole. Excellent lab work!