Fractions are written as one number above another number, separated by a horizontal line (called the vinculum).
The top number is called the numerator – this tells us the number of parts we have.
The bottom number is called the denominator – this tells us the number of parts required to make a whole.
The fraction three-eighths is written as \(\frac{3}{8}\)
3 is the numerator (the number of parts we have).
8 is the denominator (the number of parts that make a whole).
Any two numbers arranged as a numerator and a denominator separated by a line form a fraction.
Note: Your software might not allow you to write fractions as a numerator and denominator separated by a vinculum. Most software will allow you to write two numbers separated by a forward slash e.g. 3/8. For most purposes, including this course, the forward slash is just as acceptable.
When saying fractions we say the numerator first, then the denominator, with the denominator usually ending in ths. For example:
\(\frac{3}{8}\) three-eighths
\(\frac{5}{12}\) five-twelfths
\(\frac{11}{44}\) eleven forty-fourths
Fractions with denominators 2, 3 and 4 are given more familiar names:
\(\frac{1}{2}\) one-half
\(\frac{2}{3}\) two-thirds
\(\frac{3}{4}\) three-quarters