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

How do you multiply fractions?

1. Add the numerators and denominators

2. Multiply the numerators and the denominators across

3. Simply add both fractions

4. Invert the second fraction before multiplying

The correct answer is: Multiply the numerators and the denominators across

To multiply fractions, you take the numerators of both fractions and multiply them together to form the new numerator. Similarly, you multiply the denominators of both fractions to form the new denominator. This method combines the two fractions into one without altering their individual values, allowing for a straightforward calculation of the product. For example, if you multiply \( \frac{2}{3} \) by \( \frac{4}{5} \), you multiply 2 (the numerator of the first fraction) by 4 (the numerator of the second fraction) to get 8 for the new numerator, and 3 (the denominator of the first fraction) by 5 (the denominator of the second fraction) to get 15 for the new denominator. Thus, the product would be \( \frac{8}{15} \). Understanding this method is crucial, as it allows for accurate multiplication of fractions without needing to convert them to a common denominator, which is necessary for addition or subtraction, but not for multiplication.