How do I make the numbers easy to read for young kids or seniors?

Choose "Kids" or "Seniors, large and clear" in "Who colors it": numbers can then reach 15 pt (kids) or 14 pt (seniors), 22 pt for toddlers, and the key is printed at 12 pt. Then make the spaces bigger, because a number is as big as its space allows: Simpler detail, mystery mosaics (their cells are sized for the numbers), and the 8.5 x 11 trim. Atkinson Hyperlegible is the clearest font. With 4 to 8 colors a page the numbers stay single digits. Order a printed proof to check.