Free Video Timer Hack

When I’m designing digital math tasks, I feel the most ridiculous when I fire up Adobe AfterEffects — a special-effects juggernaut — to lay a simple timer over some footage for the second act.

Print Job — Act Two from Dan Meyer on Vimeo.

Here’s a neat hack if all you have is Keynote or PowerPoint.

  1. Download this video. It’s just a timer that runs to sixty seconds. (Sixty seconds, of course, is the constraint on #anyqs video.)
  2. Drag the video you want to time into Keynote or PowerPoint.
  3. Drag the timer video on top of that video. Resize and reposition it as you like.
  4. Set its animation to start with a click and stop with the next click..

Now when you play your slideshow you just click and the timer starts. Click it again and it stops. One caveat: this timer won’t do you any good if your video is slow or fast. It’s calibrated for 29.97 frames per second, which is what comes off most consumer cameras. Here’s an example of the effect in Keynote:

Timer Tutorial from Dan Meyer on Vimeo.

Drop me a line in the comments if you wind up using this.

BTW: Alternately, you could have your students get their own measurements using their phones for timers. That one’s nice because the answers spread across the measurement error a little bit. Everyone owns a slightly different answer.

BTW: I’ll be traveling over the next three weeks. My intern, Giuseppe, will be posting material for me throughout my absence and I’ll check in with the comments when I’m back.

I'm Dan and this is my blog. I'm a former high school math teacher and current head of teaching at Desmos. More here.


  1. Can you make the video as big as the slide and then export the keynote presentation as a QuickTime movie if you want to increase/decrease the playback speed after you inserted the timer? I haven’t tried this out, but it popped into my head when I was reading your post.

  2. You can also composite it together using Quicktime Pro if you have it. Open the timer, select all and copy, switch to the target video, set the playhead where you want the timer to start and goto Edit-> Add to Movie

  3. I used this video set in my first day for my physics classes. It was a great way to introduce the idea of determining what information needs to be gathered to solve a problem. It was also a great intro into the idea of rate. Thanks!