This document provides an overview of a lesson on converting units and using indices in A-Level Physics. The key learning objectives are to convert between units and their multiple and submultiples, and to correctly handle indices. Examples are given of converting between different units of length, area, volume, and density. Rules for multiplying, dividing, raising to powers, and taking roots are outlined for working with indices. Practice problems apply these rules for simplifying terms with indices and writing expressions as single powers.