Our Science and Technology challenge was to design an egg-cosy that would keep our boiled eggs warm.  The children talked about the best materials to use to make their cosy and then designed it in their booklet.  They then had to cut out fabric using a template and sew their cosy together before adding their decoration.  We tested the cosies and found that they kept an egg at 70 deg for a few minutes whereas the eggs without cosies cooled to 60 deg in the same time.  A successful challenge!  The children all loved their cosies and were rightly proud of their achievement.