SI units and conversion rules
SI units and conversion rules

Physics equations usually work best when every value is in SI units such as metres, kilograms and seconds. A physical quantity is what you measure, and the unit tells you the scale of that measurement.
Step-by-step lessons on Edexcel GCSE Physics 1.1.2 Unit prefixes, conversions, significant figures and standard form. Each one builds up to exam-style questions. Master the required practical work and core equations early, since both papers can draw on content and maths skills from across the whole specification.