Google Voice in the German classroom

I have set up a Google voice account and had my 8th graders call in and describe their clothing to me in German.  I think it worked very well with 2 exceptions:
1.  I gave the kids the wrong number the first time (!), so it didn't work (obviously!).

2.  There are still about 20% of the kids who didn't call in at all and have a 0 on the assignment.  I think this number will decrease as I give more of these assignments.

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