Just for fun – this is Emily’s Calculator.
All the numbers are colour-coded to their lowest prime factor according to Emily’s colour scheme.
Emily doesn’t tackle zero as she interested in counted things that exist in the world. Zero is coloured black as it has a very special status of its own.
This is an example of a square of numbers, similar to a small times table, where the highest number in the top-right corner is the square of the number in the bottom-right corner.