Run a whole-school, cross-curricular competition to observe Switch Off Fortnight! This series of 6 differentiated math and science worksheets with answers and certificates will allow all students in your school to take part. Sheets are differentiated by colours of the rainbow; younger students can opt for red level while your most experienced mathematicians and scientists can opt for indigo level. Red level asks pupils to add single digit numbers and double single digit numbers. More able students may wish to have a go at the Indigo extension task which gives them a taste of (modified) GCSE physics equations to calculate the running costs of appliances. Two certificates are supplied: one for pupils earning 100% on their entry and one for everyone who took part.