What happens when zero is in the denominator of a fraction?

When zero is in the denominator of a fraction, it results in an undefined number. In mathematics, division by zero does not yield a valid or meaningful result. This is because division can be interpreted as asking how many times a number can fit into another number. If you try to divide by zero, you are essentially asking how many times zero can fit into another number, which cannot be determined since zero cannot be multiplied by any number to achieve a nonzero numerator. Therefore, the concept of a fraction with zero in the denominator is undefined in mathematics, making the statement about it resulting in an undefined number accurate.

The other options do not reflect the principles of division correctly. For instance, stating that it equals zero either misinterprets the operation or suggests an incorrect mathematical outcome, as division by zero is not permissible. Similarly, describing it as a repeating decimal or suggesting that it can be calculated normally both contradict the foundational rules of arithmetic that delineate proper operations involving zero.