Their first way of writing numerals is supposed to be based on how they're represented in an abacus. Their version of it is simply a wooden box with compartments for stones—you don't have beads sliding on rods like the Chinese do. As in on the Chinese abacus, a stone above the horizontal divider represents 5 and a stone below the divider represents 1. It is big-endian, but since the language is written from right-to-left the largest place value goes on the right and the smallest place values go on the left. This is a true place-value system, and there are no implicit zeroes. This, for example, is the deliberately arbitrarily large number JIHG,FEDC,BA98,7654,3210 in vigesimal (in decimal it's 104,567,135,734,072,022,160,664,820)—they only have words for numbers up to eight vigesimal digits yet. I apologize for the lines not being perfectly straight.
The actual arrangement and orientation of the dots doesn't matter so long as they're all there and in the right place according to the rules. There are ways to represent fractions, but for the simplicity of discussion I'm mostly limiting this to integers.
Now the Westforesters are supposed to live in an empire that lasts a long time by my conworld's standards—nearly two millennia. Over the years, they start thinking that drawing all those lines and putting in all those dots is a little tedious, so they do some cursive simplifications and arrive at something like this:
The circle for 10 is not transparent and perhaps requires an explanation. One way of representing fractions with "abacus numerals", as I call them, is sexagesimally: circles are used instead of dots to distinguish between the two uses (it's supposed to reflect the use of different-colored stones), and each circle above the divider represents 10 instead of 5 (each circle below the divider still represents 1).
I'd like some comments on the numeral system in general and whether this is a plausible development. I still see some room for improvement—in particular, I think some of the digits could do with being a little more distinct from each other so smaller digits are harder to fraudulently change to larger digits—that motivated some of the changes in my first draft (I was going to ask if the 1 should slant the other way—having it perfectly vertical is not an option since a vertical line is now supposed to represent the "vigesimal point"—but before I posted I realized it can still be changed easily to an 18 either way.) What do you think?
