Assessment and Learning in Knowledge Spaces (ALEKS) Basic Math Placement Practice Test

What is the first step in adding or subtracting fractions?

1. Multiply the denominators

2. Set the denominators to one

3. Make the denominators the same

4. Invert the fractions

The correct answer is: Make the denominators the same

The first step in adding or subtracting fractions is to make the denominators the same. This is essential because fractions can only be added or subtracted directly when they have a common denominator. When the fractions share a common denominator, you can focus on adding or subtracting the numerators while keeping the denominator constant. For example, if you want to add \( \frac{1}{4} \) and \( \frac{1}{2} \), you cannot directly add them because the denominators (4 and 2) are different. Instead, you would convert \( \frac{1}{2} \) to an equivalent fraction with a denominator of 4, which would be \( \frac{2}{4} \). Now, both fractions can be easily added: \( \frac{1}{4} + \frac{2}{4} = \frac{3}{4} \). This step of finding a common denominator ensures that the fractions are comparable and can be summed or subtracted correctly, which is foundational for mastering operations with fractions.