1. The problem asks for the sum of the first $n$ integers, from 1 up to $n$. 2. The formula to find the sum of the first $n$ natural numbers is: $$ S = \frac{n(n+1)}{2} $$ 3. This formula works because when you pair numbers from the start and end (1 and $n$, 2 and $n-1$, etc.), each pair sums to $n+1$, and there are $\frac{n}{2}$ such pairs. 4. For example, if $n=5$, the sum is: $$ S = \frac{5(5+1)}{2} = \frac{5 \times 6}{2} = 15 $$ 5. So, the sum of integers from 1 to $n$ is always $\frac{n(n+1)}{2}$, which is a quick and efficient way to calculate it without adding each number individually.