The Ýäwúrêýí use only the numbers 1 through 8 to form all other numbers.
For numbers 9-15 you do 8 and then whatever you add to it to get the number (after the 8).
For 16, 24, 32, 40, 48, 52, 60, 64 place the number you multiply 8 by before the 8.
For intermediate numbers combine the two as in 19 = 2 8 3.
For numbers greater than 64 do the 9+ formation first, then a raised dot, then the 8, another dot and the number you add so 100 = 8 4 · 8 · 4