What is an effective and practical means to teach about natural logarithms and log laws to high school students? My students are quite practically minded, and I have found that teaching them concepts in a practical manner to be very helpful (maths 'experiments'; modelling on the smartboard etc). I am looking for a practical means (hands on preferably) to teach about the log laws of natural logarithms.

For introducing logarithm, perhaps something like starting with exponential population growth and then noting that the graph is linear in log-space?

You can then change back and forth between representations and see how things like base-change affect the plot and the interpretation.

This is also probably representative of where less-mathematical scientists run into logarithms the most.