Last week we finished our science unit on structure and function with a final challenge, to design a  paintbrush.  We started by brainstorming different things we might like a paintbrush to do from painting skinny lines to bubble circles and even magically painting an object lots of different colors at once.  (I think some student ideas were inspired by the book "Artdog").  Next, children were invited to draw a paintbrush design.  They then had an opportunity to choose from a variety of materials and build their own paint brushes.  When they were complete, everyone had a chance to share their paintbrushes  and talk about challenges they faced in making them.  We also noticed similarities and differences among all the different designs.  Some children had fun testing the brushes and comparing the ways different models painted.