The Wratten numbers are used to classify photographic filters.

There are many silent numbers in the phone book.

The library has a large collection of call numbers.

I have multiple dial numbers saved on my phone.

The Bernoulli numbers are a sequence of rational numbers that appear in many different areas of mathematics.

There are many untouchable numbers in mathematics.

The oxidation numbers of the elements in the compound are different.

The student numbers have increased significantly this year.

Liouville numbers are a set of transcendental numbers with a specific property.

Sierpinski numbers are a set of numbers that satisfy a certain property.