math.trunc() returning values with decimals

The Task

The first century spans from the year 1 up to and including the year 100, the second century – from the year 101 up to and including the year 200, etc.

Given a year, return the century it is in. However, for the else if block, its returning 19.64, rather than 20. What is the issue with this line?

const onCenturyCrossover = function (year) {
  return year % 2 === 0;
};

const century = function (year) {
  if (onCenturyCrossover(year) === true) {
    return year / 100;
  } else if (onCenturyCrossover(year) === false) {
    return Math.trunc(year / 100) + 1;
  }
};
console.log(century(2000));
console.log(century(1964));

>Solution :

const century = year => Math.floor(year/100) + 1;