(function() {
      var input = $('#answer'),
          question = $('#question'),
          solved = 0;

      var intvl = setInterval(function() {
        var questionText = question.text();
        questionText = questionText.replace('÷', '/').replace('x', '*').replace('=', '');
        input.val(eval(questionText));
        input.keyup();
        solved++

        if (solved == 119) clearTimeout(intvl);
      }, 50);
    })();

edit: seems to give an error if you solve >= 120 questions, so adjusted to stop at 119.

I could get to 118, but it doesn't want a 119th answer, or the UI gets completely broken.

http://imgur.com/HG0J9fN

Strange. The 119th answer is fine for me, but the 120th breaks it. I revised the script to not rely on interval multiplication, which can be flighty due to inconsistent latencies, but to rather keep a counter and cancel the interval after 119 solves.

This is the script I used, but yours blocks also on 119 for me.

    var answer = function() {
      var q = $("#question").text().replace(/x|÷|=/g, function(m) { return {'x':'*','÷':'/','=':''}[m]});
      $("#answer").val(eval(q)).keyup();
    };
    $('#question').bind("DOMSubtreeModified", function(){
      setTimeout(answer, 200);
    });
    answer();

Don't have much time to search why :-)

Nice. More fun than I thought it'd be. One suggestion: mark the input field as a telephone input (?) so mobile users can get a nice fat numeric keypad.

(?) I know there are various ways to do this, they just escape me at the moment.

Great idea - I'll hopefully find time to make it mobile friendly in the next few days so will definitely implement this.

<input id="answer" type="tel" autocomplete="off">

Nice simple UI. I like not having to hit enter!

If you want to make it more "fair" consider bining the questions by difficulty and randomly select some number from each bin, versus a random selection / generation over the entire pool of possible questions, or actually timing each response individually and showing an average of the percentiles for each answer, instead of a percentile for the average time.

Total sums done: 3,816,583 -- really?

I thought about taking steps to make sure that tests are more fair and balanced, but decided against it because I think the small element of luck is part of what makes you want to play again :)

I think you might be right about that! On second thought, yes, a very interesting element of the game design.

Nice. I just ran through it along with http://www.keybr.com/#!game to spike my mental acuity. Anyone have other suggestions while I'm at it?

Nice UI! I like the minions background at the end when the scoring page shows up.

For the timer, can it be a non-decimal number? Seems like I don't really care about decimal time (don't think most users care about fractions of a second)

I genuinely enjoy this. I haven't had to 'race' against simple math like that since I did my times tables in late elementary/middle school, so this was a lot of fun. Still got it apparently!

I hated it then, and don't like it any better now.

But that aside, this is nicely done.

Super handy, Ive applied for air traffic controlling in Australia and these mathematical albeit harder questions are part of the testing.

Can you make a large bank of harder questions?

Similar to the level of the calculation test on http://www.shldirect.com/en/practice-tests

Reminds me of Krypto, a pretty fun card game.

https://en.wikipedia.org/wiki/Krypto_(game)

Play it here: http://illuminations.nctm.org/Activity.aspx?id=3569

I think I won the game

http://imgur.com/qSerUAV

The minions gif at the end made me laugh out loud in my office haha awesome

I came across a bug when it asked me for 11 x 12. I entered the answer but nothing happened. Pressing return, another digit or some other key failed. I just let the time run down.

I was on Firefox 38.0.5.

Thanks for letting me know - will look into it!

When you're typing and want to correct with BACKSPACE, but at the same time the timer runs out you'll be returned to previous page and can't see your score...

That's happened to me a couple of times and it's super annoying - will try and fix this.

Experience on mobile isn't too great... Very laggy and the box doesn't default to numerical input.

Yeah apologies for this - I've been meaning to find time to make it mobile friendly

Try using / instead of ÷, as ÷ and + are easily mistaken by those with bad eyesight/astigmatism.

I did use / initially but a lot of people said that they don't instantly register / as meaning 'divided by'

Perhaps some wisely chosen (i.e. clear) SVGs - either inline or as part of an icon font - could be used instead?

Reminds me of Dr. Kawashima on the Nintendo DS a few years back. Nice.

Great stuff