For in loop help

/*

Write a for in loop that deletes every property from the object deleteTheBigNumbers whose value is greater than 100.

*/

//Code Here

function removeBig(obj){

  for(let key in obj){

    if(obj[key]>100){

      delete obj[key];

    }

  }

  return obj;

}

removeBig(deleteTheBigNumbers);

Why is this not solving the problem?

// Do not edit the code below.

var deleteTheBigNumbers = {

first: 10,

second: 20,

third: 110,

fourth: 200

}

// Do not edit the code above.

/*

Write a for in loop that deletes every property from the object deleteTheBigNumbers whose value is greater than 100.

*/

//Code Here