Even the most mundane objects to adults can be very interesting to elementary age children. Something as simple as a paper clip can turn into a discussion of the properties of metal, why the design works so well and how it could be improved. Try each day to pick up something (my desk would supply a year's worth of ideas on its own) to share with the class and ask them questions: what is it, how does it work, what is it constructed of and how could it be redesigned?