Originally Posted by Nutmeg
I have a question. Is there a way to acquire all these decipher tables in-game?
There isn't a "Rosetta Stone" exactly for the numerals, you have to extrapolate from the instances they DO give you.
I started by learning (one of) the shape(s) for 5 from the Industrial zone because it has a picture of the symbol and then spells out the word "five" in the more-easily deciphered alphabet. Then, with that in mind, you can find a series of addition equations in a class room. These help you work out 1, 2, 3, 7, and 10. In the same classroom there is a poster which hints that there are multiple ways to write some of the numbers. It gives you the two ways of writing 3. From there, it was like I detailed in my post above.
EDIT: But the alphabet and tetromino/button combos do have places where it shows you the entire mapping.