Question

What does ! mean in a math problem?

It is an exciting problem.

Subtract each number in sequence from that number to 1.

Add each number in sequence from that number to 1.

Divide each number in sequence from that number to 1.

Multiply each number in sequence from that number to 1.

Answer 1

In mathematics, the symbol "!" represents the factorial of a number. The factorial of a non-negative integer \( n \) (denoted as \( n! \)) is the product of all positive integers from 1 to \( n \). For example:

- \( 0! = 1 \) (by definition)
- \( 1! = 1 \)
- \( 2! = 2 \times 1 = 2 \)
- \( 3! = 3 \times 2 \times 1 = 6 \)
- \( 4! = 4 \times 3 \times 2 \times 1 = 24 \)
- \( 5! = 5 \times 4 \times 3 \times 2 \times 1 = 120 \)

So, to clarify the options you provided:

1. **Subtract each number in sequence from that number to 1**: This does not describe factorial.
2. **Add each number in sequence from that number to 1**: This also does not describe factorial.
3. **Divide each number in sequence from that number to 1**: This does not describe factorial either.
4. **Multiply each number in sequence from that number to 1**: This is the correct interpretation of factorial.

Therefore, the correct description is "Multiply each number in sequence from that number to 1."