The expression "n(n + 1)" represents a mathematical formula where "n" is a variable that can take any integer value. This formula is often used to calculate the product of a number and its consecutive integer. For example, if n = 3, then n(n + 1) equals 3 × 4, which equals 12. This expression is significant in various areas of mathematics, including algebra and combinatorics. It can also be used to find the sum of the first n natural numbers, as the result of n(n + 1) divided by 2 gives the total sum.