FTCE General Knowledge Math Practice Test

What is the result of multiplying a number by its inverse?

1. 0

2. 1

3. The original number

4. The inverse of the number

The correct answer is: 1

Multiplying a number by its inverse always results in 1. The inverse of a number is defined as the value that, when multiplied by the original number, yields the multiplicative identity, which is 1. This concept is fundamental in mathematics, particularly in understanding fractions and rational numbers, where for any non-zero number \( x \), the inverse is \( \frac{1}{x} \). When you perform the multiplication \( x \times \frac{1}{x} \), you arrive at 1. Therefore, the correct answer accurately reflects this property of numbers and their inverses.