Calculating with functions

gistfile1.txt

function zero(exp) { return numberExpression(0, exp); }
function one(exp) { return numberExpression(1, exp); }
function two(exp) { return numberExpression(2, exp); }
function three(exp) { return numberExpression(3, exp); }
function four(exp) { return numberExpression(4, exp); }
function five(exp) { return numberExpression(5, exp); }
function six(exp) { return numberExpression(6, exp); }
function seven(exp) { return numberExpression(7, exp); }
function eight(exp) { return numberExpression(8, exp); }
function nine(exp) { return numberExpression(9, exp); }

function numberExpression(num, exp)
{
  return exp == undefined ? num : exp(num);
}

function plus(addend) { return function(augend)  {  return augend + addend;  } }
function minus(addend) { return function(augend)  {  return augend - addend;  } }
function times(addend) { return function(augend)  {  return augend * addend;  } }
function dividedBy(addend) { return function(augend)  {  return augend / addend;  } }