Definition of denominator

The denominator is the number written below the fraction bar that tells how many fractional parts there are in the whole or the set.

For example, suppose you cut a pie into 6 equal pieces. There are now 6 fractional parts in the whole. Therefore , your denominator is 6.

More examples

1 ) Suppose you read half of a book, what is your denominator? Your denominator is 2 since the whole book is now divided into 2 equal parts. 

2 ) Suppose you invite 20 people to a party and only 3 of those people showed up, what is your denominator? You denominator is 20 since there are 20 fractional parts in the set. Simply put, your set has 20 people.

Your denominator is always going to be the total number of pieces, items, parts, and so forth ...