# Compare Fractions, Cross-Multiply

## What Is The Best Method To Compare Fractions And Look At Cross-Multiply?

If your are **Comparing Fractions** with the same denominator, the Fraction with the largest numerator is the Fraction of greatest value; for example ^{3}/_{8}
is smaller in value than ^{7}/_{8}; think of a pizza, the first
pizza has 3 slices but the second pizza has 7 slices. Seven slices of pizza is more
than 3 slices.

When the denominators of two fractions are different, determining the larger value
Fraction is not as simple. Before we investigate how to
solve this type of problem, there is a rule that is important to understand. Rule: multiplying or dividing the numerator AND denominator of a fraction by the same number does not change
the value of the fraction. We will show in the following example that ^{1}/_{2}
= ^{2}/_{4}.

When comparing fractions to determine if they are equal or Equivalent Fractions, follow these simple steps:

- First
**Cross-Multiply**: (1) multiply the numerator of fraction one by the denominator of fraction two. (2) multiply the denominator of fraction one by the numerator of fraction two. If the two products from the multiplication are equal, the two fractions are Equivalent Fractions. Here is an example.

$\text{Fraction One:\hspace{0.5em}}\frac{\mathrm{18}}{\mathrm{21}}$

$\text{Fraction Two:\hspace{0.5em}}\frac{\mathrm{30}}{\mathrm{35}}$

$\text{Cross-Multiply Fractions}$

$\text{One and Two}$

$\text{18 x 35 = 630}$

$\text{21 x 30 = 630}$

$\text{We got the same product}$

$\text{(630) from both fractions.}$

$\text{These fractions are equivalent.}$

- If the product resulting from the cross-multiply
are not the same for both fractions, the fractions are not Equivalent Fractions. Then the larger
fraction is the one with the largest numerator - denominator product. Example:

$\frac{3}{7}\hspace{0.5em}\hspace{0.5em}\frac{2}{5}$

$\text{3 \xd7 5 = 15}$

$\text{7 \xd7 2 = 14}$

$\text{Fraction 3/7 is greater}$

$\text{in value than fraction 2/5.}$

Please Read! These are instructions to input fractions into the calculator to compare their values: An fraction can be typed in this formatted. Example: 5/10, 26/30, etc.