When we evaluate math expressions, it is important to know what each part of the expression is called. Fractions have two parts, the top number and the bottom number. The bottom number in a fraction is called the denominator. We can better understand and discuss the math we must solve when we know the correct terms.
Whenever someone talks about the denominator, they are talking about the bottom number in a fraction. Look at this fraction:
The denominator is 3. Now look at this fraction:
We could say that 25 is 5 times the denominator.
Think about these fractions:
We can tell that the denominators are 9, 5, and 8.
In fractions that equal one, the top number (numerator) is always the same as the denominator. In fractions that equal a whole number, the top number is always a greater (larger) number than the denominator. When we are changing fractions into whole numbers, we find out how many times greater the top number is than the denominator. In the fraction 
, the top number is 4 times greater than the denominator. The denominator, 4, multiplied by 4 is equal to 16. We must remember that when someone mentions the denominator, he or she is talking about the bottom number of a fraction.
