A better way to teach making a timer

Last year I taught my 6th graders how to make a timer for an application we were making by using all of the primitives available. So I showed them how to use resett and print the time every. second with 'timer / 10'. I missed a great opportunity that I'm finally talking advantage of. In one fell swoop I can teach them how Logo can do math, loop, and use variables. Here's the model for the timer we're working with now:

to start-timer
make "seconds "0
repeat 60
[time, pr :seconds
wait 10
ct
make "seconds :seconds + 1]
end

With this approach my students this year are getting what were doing, much better than last year.