text: // Let's do some grade-school math.
  // Actually: let's have the computer do the math for us :)
  // This page may be helpful for this exercise:
  // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
  
  
  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Create a function "add99" that takes one argument and adds the number 99 to it.
  // You can assume that the argument passed in will be a number value.
  
  function add99 (num) {
  
  return 99 + num
  
  } 
  
  add99(1)
  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Create a function "sum" that takes 2 arguments and sums them together.
  // Assume that both arguments are numbers.
  
  function sum (x,y) {
  
  return x+y
  
  }
  
  sum(1,2)
  
  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Create a function "difference" that takes 2 number arguments and returns their
  // difference.
  // ie: the second number substracted from the first number
  
  function difference (x,y) {
  
      return x-y
  }
  
  difference(99,1)
  
  
  
  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Create a function "multiply" that takes 2 number arguments and returns their
  // product.
  
  function multiply (x,y ) {
  
  return x*y
  
  }
  
  multiply(4,3)
  
  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Create a function "divide" that takes 2 number arguments and returns the
  // division of the first argument by the second.
  
  function divide (x,y) {
  
  return x/y
  
  }
  
  divide(8,4)
  
  
  // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // The modulus operator (%) works like remainder from division.
  // Create a function "mod" that takes 2 number arguments and returns the
  // remainder of the first divided by the second.
  
  function mod (x,y) {
  
      return x%y
  
  }
  
  mod (5,3)