Counting is the first thing arithmetic asks for and close to the last thing it stops asking for. The boards on this shelf run from a hundred square where a times table paints itself to a hunt in which the only information you ever get is how far away something is.
They are ordered by how much counting you want behind you already. Stained Glass assumes none: it starts the count at the top of the board and the colours tell you whether you were right. Finding Zero and Finding the Longest need very little arithmetic and a great deal of care about what a number you have already spent a turn on actually tells you. Slug Salad keeps a running total on a leaf and makes you check it.