Answer:
public static int summation(int low, int high) {
    int sum = 0;
    for(int i=low; i<=high; i++) {
      sum += i;
    }
    return sum;
  }
Explanation:
- Initialize sum variable to hold the sum
- Inside the for loop which iterates from low to high, calculate the sum of the numbers between low and high
Then:
- Return the sum