# You’ll never use what you don’t know

Frequently, I hear adults who should know better argue against learning something, whether it is algebra, analysis of variance or learning a programming language. They say,

I’m 47 years old and I’ve never used (insert thing I didn’t learn here).

Yes, that is true. However, if you had learned it, there is a good chance that you would have used it .  For those of you protesting, “Hey, I learned algebra!” , maybe you did and maybe you didn’t.  Read my post on number sense.)

Let’s take this morning as an example. In keeping with my New Year’s Literary resolution, I started out the day reading the jQuery cookbook. There were two things I learned that I expect to use this year. One of them was very simple, but I didn’t know it.

var t1 = +new Date ;

This returns the current date in milliseconds converted to a number. Yes, you could use the Javascript Number() function but this saves you a step.

Now you can use this useful bit of code which I am planning on applying next week when I get done with what I’m working on now. I can use it to see how long a student worked on each individual problem and how long he or she took for the whole test.

```(function() { var log = [], first, last ; time = function(message, since) { var now= +new Date ; var seconds = (now - (since || last)) /1000 ; log.push(seconds.toFixed(3) + ':' + message + 'br/>') ; return last = +new Date ; }; time.done = function(selector) { time('total', first) ; \$(selector).html(log.join('')) ; }; first = last = +new Date ; })() ; ```

Now, the author’s interest was in seeing how long each bit of code took to run. However, I can see how this could be really useful in the pretest and posttests we use for our games to see how long the student spent on each problem. We could call this function each time the student clicks on the next arrow to go to the next problem.

One of the Common Core Standards for mathematical practice is “Make sense of problems and persevere in solving them.”

How do you know if a student is “persevering”? One way would be to measure how long he or she spent on a particular problem before going on to the next. We cannot know for a fact that the student spent time thinking about it rather than staring off into space, but we can at least set a maximum amount of time the student spent thinking about it before going on to the next thing.

While there is truth in that, I would say that much more that counts can be counted and much more of data can be turned into statistics if you know how to do it.

Learn how.