Functions, isOdd Solution- possible solution mistake?

The Functions- isOdd Solution- does’t seem to account for decimal numbers.
The solution code given by app academy is below:

function isOdd(number) {
  return (number % 2 !== 0);
}
function isOdd(number) {
  if (number % 2 !== 0) {
    return true;
  } else {
    return false;
  }
}

if I pass in a decimal number into the isOdd() function, I get true.

console.log(isOdd(4.2))