A great activity that will get kids out of the house during vacations (and away from computer games) is hunting for “treasure” with a metal detector. This winter, after some R&D work I finally worked out a design that would be easy enough for youngsters to make and use, but still powerful enough to find small things like coins.
(The technical details of it
will be posted soon have been posted in a separate post here.)
Although the electronics work was not totally new to them (these students had made the morse key project earlier) it still required close supervision, so we only ran two small classes of three students each. About fifteen hours was needed to complete the project.