Try these games to warm yourself up:
http://www.math-play.com/Factors-Millionaire/Factors-Millionaire.html
http://www.crickweb.co.uk/ks2numeracy-shape-and-weight.html#triangles
http://www.bbc.co.uk/schools/teachers/ks2_activities/maths/shapes.shtml
http://www.bbc.co.uk/bitesize/ks2/maths/shape_space/2d_shapes/play/