Getting+Attention+During+Labs

I just returned from the National Middle School Conference and gleaned several new strategies. If you need to get the attention of your students while they are busy in the lab, just say in a normal volume, "If you can hear my voice, clap 3 times." After some students clap, repeat or vary the directions. I have been repeating the directions with "2 times". The students have been stopping to see what the clapping is all about and I am able to give them the needed directions at that time.

Give it a try and let us know how it works....or....what strategy works for you?