Just try out the Boss DR670 (there are Cheaper ones and I aint using it)
I just practize with a drumcomputer myself, it works great.
My Drumteacher plays the Boss thing and at first I was amazed how nice it sounded. (Mortician used it on a few records)
I dont really think that that would help, so you should explain him about 4th notes 8th, 16th etc. And he has to count...
So I´m not a drum teacher but I hope that will help a little.