Math From Scratch 0009: Cosets and Lagrange’s Theorem

Part nine of a number that I hope will be finite: Cosets and Cardinality. Remember, past lessons can all be found by clicking on the “math from scratch” tag below. Also, try as I might, I couldn’t find a natural ZZ Top reference to work into this lesson dealing with Lagrange’s Theorem. Suggestions are welcome in the space below.