This data is used as a reference value.

This document is very important.

I read the letter from him.

Please write your name with a marker pen.

Discrete mathematics is an important field that forms the basis of computer science.

He is majoring in applied mathematics at university.

He is passionate about researching pure mathematics.

He is a world-famous mathematician.

Combinatorics is a branch of mathematics that studies combinations of things.

Combinatorics is a branch of mathematics dealing with issues of order and choice.