Is 4/5 Bigger Than 1/8?

Method 1: Common Denominators

To compare these fractions, we need a common denominator. The denominators are 5 and 8, and the least common denominator (LCD) is 40.

• Step 1. Convert \(\frac{4}{5}\): multiply numerator and denominator by 8.
  \[\frac{4}{5} = \frac{4 \times 8}{5 \times 8} = \frac{32}{40}\]
• Step 2. Convert \(\frac{1}{8}\): multiply numerator and denominator by 5.
  \[\frac{1}{8} = \frac{1 \times 5}{8 \times 5} = \frac{5}{40}\]
• Step 3. Compare the numerators: 32 vs 5.
• Step 4. Since 32 is greater than 5, we know that \(\frac{4}{5} > \frac{1}{8}\).

Method 2: Cross Multiplication

A quicker way to compare fractions is to cross-multiply. Multiply each numerator by the other fraction's denominator:

• Step 1. Multiply the numerator of the first fraction by the denominator of the second: \(4 \times 8 = 32\).
• Step 2. Multiply the numerator of the second fraction by the denominator of the first: \(1 \times 5 = 5\).
• Step 3. Compare the products: \(32 > 5\), so \(\frac{4}{5} > \frac{1}{8}\).

Method 3: Decimal Comparison

Convert each fraction to a decimal by dividing the numerator by the denominator:

Since 0.8 is greater than 0.125, we confirm that \(\frac{4}{5} > \frac{1}{8}\). In percentage terms, \(\frac{4}{5}\) is 80% and \(\frac{1}{8}\) is 12.5%, a difference of 67.5 percentage points.

Why Does This Work?

These fractions have different numerators and different denominators, so we can't compare them directly. By converting to a common denominator of 40, we're cutting both quantities into equal-sized pieces. Then 32 pieces vs 5 pieces is a straightforward comparison.