How to calculate digit sum by C++

Basic Approach Let's take 2026 as an example. 2026 can be written as 2020 + 6. Since 2020 is divisible by 10, dividing 2026 by 10 leaves a remainder of 6. Using this property, we can extract the digit in the ones place. Here is the code example: #include <bits/stdc++.h> using namespace std; int main(){ int digit = 2026; // digit = 2026 (2020 + 6) cout << "ones place: " << digit % 10 << endl; digit /= 10; // digit = 202 (200 + 2) cout << "tens place: " << digit % 10 << endl; digit /=10; // digit = 20 (20 + 0) cout << "hundreds place: " << digit % 10 << endl; digit /=10; // digit = 2 cout << "thousands place: " << digit % 10 << endl; } Output: ones place: 6 tens place: 2 hundreds place: 0 thousands place: 2 Streamlined Implementation We can simplify this step using a while loop. Since each division by 10 removes the last digit, the number will eventually become 0. #include <bits/stdc++.h> using namespace std; int main(){ int digit = 2026; while (digit > 0) { cout << digit % 10 << endl; d