Ok I know one way of using the formula n*(n+1)/2) and have used it to calculate the sum already but I just wanted to know how I can access many numbers in a loop and add them together. Here is what I did so far.

Code:#include <iostream> using namespace std; int main (){ int num, num1, sum; cout<<"Please enter a number\n"; cin>>num; cout <<"Please enter the number to which you want to count\n"; cin>>num1; for (; num<=num1; num++) cout<<num<< ","; //I do get the numbers but from here //I want to know what I can do so that I can add each // of these numbers together? do (sum=num+num);//I want to add them like 0+1+2+... //tried using loops but couldn't get it while (num<=sum); cout<<sum;//but this does not work so any help is appreciated return 0; }