addWithLoops.js

const addWithLoops = x => {
  // initializes variable sum to 0
  let sum = 0
  // loop through all numbers 0 to 100
  for (let i = 0; i <= x; i++) {
    // checks each number if is divisible by 2
    if (i % 2 === 0) {
      // adds number to variable sum if it is
      sum += i
    }
  }
  // return grand total
  return sum
}

console.log(addWithLoops(100)) // 2550