Different questions have different numbers. Arabic numerals are commonly used in general mathematics, such as five 1 is five; The first unit in mathematics is the arithmetic concept, which is the so-called whole "1".

What's the difference between "one" and "1": "one" is the expression of numbers in Chinese characters, which is more common in non-mathematical and economic articles, and "1" is an Arabic number, which was originally expressed by Arabs and has been widely used all over the world.