How to Use Models to Decompose Fractions into Unit Fractions?

A Step-by-step guide to using models to decompose fractions into unit fractions

Unit fractions are rational numbers written down as fractions where their numerator is \(1\) and their denominator is a positive integer.

Decomposing fractions into unit fractions can be a helpful way to break down more complex fractions into simpler components. A unit fraction is a fraction where the numerator is 1, and the denominator is a positive integer. Here’s a step-by-step guide to using models to decompose fractions into unit fractions:

Step 1: Choose the fraction to decompose

Select the fraction you want to decompose. For this example, let’s use \(\frac{3}{4}\).

Step 2: Create a model

Draw a rectangle or circle to represent the whole. For our example, we’ll draw a rectangle. Divide the rectangle into equal parts based on the denominator of the fraction (in this case, 4 parts). Shade the number of parts equal to the numerator (in this case, shade 3 parts).

Step 3: Identify unit fractions

Now that you have a visual representation of the fraction, you can see that each part represents a unit fraction. In our example, each part represents \(\frac{1}{4}\), since the rectangle is divided into 4 equal parts.

Pre-Algebra for Beginners 2026 The Ultimate Step by Step Guide to Preparing for the Pre-Algebra Test

Download

$27.99 Original price was: $27.99.$17.99Current price is: $17.99.

Rated 4.30 out of 5 based on 105 customer ratings

Satisfied 92 Students

Step 4: Write the decomposition

Write the decomposition of the fraction as the sum of the unit fractions that make it up. In our example, we have: \(\frac{3}{4} = \frac{1}{4}+ \frac{1}{4} + \frac{1}{4}\)

Step 5: Confirm the result

Make sure that the sum of the unit fractions equals the original fraction. In our example, we can see that \(\frac{1}{4} + \frac{1}{4} + \frac{1}{4} = \frac{3}{4}\), confirming that our decomposition is correct.

Keep in mind that there can be multiple valid decompositions for a given fraction. For example, \(\frac{3}{4}\) can also be decomposed into \(\frac{1}{2} + \frac{1}{4}\), as both of these unit fractions sum to the original fraction. Models can help you visualize and understand different ways to decompose fractions into unit fractions.