.calculadora{
  display: block;
  background-color: black;
  margin: 100px;
  padding: 20px;
  width: 235px;
  height: 335px;
  border-radius: 10px;
}
.calculadora td button{
  display: block;
  width: 50px;
  height: 50px;
  font-size: 15px;
}

#display{
  display: block;
  text-align:right;
  font-size: 40px;
  margin-bottom:20px;
  width: 210px;
  height: 75px;
  line-height:100px;
  background-color: white;
  border-radius: 5px;
}