As sound increases the clapping goes faster.
 

After programming the RCX to data log sound these students found the classroom, when quiet, could get as low as 45 decibels.  However when they went to another room and asked for loud sounds the readings were up to 104 decibels.

The green house was programmed to data log.  It also had a door that opened when the temperature was above 80 degrees and closed when the temperature was below 79.