As Math.log currently stands, it’s a bit useless. It only calculates natural logarithms (base e). We can easily modify it however, to calculate logarithms of any base:

```
Math.log = (function() {
var log = Math.log;
return function(n, a) {
return log(n)/(a? log(a) : 1);
}
})();
```

We can now specify the base as a second parameter, or still use the default one (Math.E) if we don’t specify one, so older scripts won’t break or if we want a shortcut to the natural logarithm. ;)