GNC converts modern Arabic (international) numeral ► Greek numeral.
GNK converts Greek Numeral ► Arabic (international) numeral.
The keyboard input system isn't like the decimal system we use everyday, this has different sequence. Therefore, in order to filter incorrect input, it will just add the number value from the clicked button.
It's kinda not like today's numeral system (modern Arabic -- straight forward 0-9 decimal), and it's using Greek letter (numeral). And to make it different than just letter (to form a word or not, but not number), it has that symbol that looks like an apostrophe but it's not, behind the number sequence.
And there's the M, as in Myriad, for the power of 10,000. It's not like M in Roman, which is 1,000.
So we use the power of 10, right, like 1,234 = [1 × 103] + [2 × 102] + [3 × 101] + [4 × 100] = 1,000 + 200 + 30 + 4.
The Greek numeral system in that time was not exactly like in our period. They had a letter representation for each number until 9,000. You can see on the table above. So, after 9,999 is Myriad (M) or alpha Myriad (αM). And so forth.
The format for Myriad is usually using that superscript writing format with the numbers (multipliers) are above the M letter. This one just rises the numbers position a bit and put color on them so that you know it's the Myriad part.
As you can see from the 3 last examples, each has Myriad in it. The alpha before the Myriad is the exponent or power, in this case 1 (α). So it has 10,0001. If the value is one hundred million, for instance 100,000,000 ► βMαʹ (beta myriad alpha) ► 10,0002 × 1 = 100,000,000.
Keep in mind, if there's M, then the letter before M will be used as the exponent.
If there's one M and no letter written before it (on left side), meaning 10,000 powered by α (1).
Like 1x or 1a is written as x or a, sort of.
And for formatted (using pen and paper) writing, the exponent before M can be omitted.
There's β (2) in front of first M and α (1) in front of second M.
Also can be written as M͵αM͵α͵αιαʹ (without the exponent in front of M, semi-formatted).
There's α (1) in front of first M.
Also can be written as Mιε͵βραʹ (without the exponent in front of M, semi-formatted).
Pay attention on how the grouping technique works for letter surrounding the M (10,000) above. The multiplier sequence for Myriad: thousands ► hundreds ► tens ► ones.
We don't need to group it, it doesn't have myriad part.
As you probably notice, the power (exponent) notation is the opposite version of what we use today. We directly use 103 for 1,000 for example, but not in Greek numeral. It has that right to left writing system feeling, but not really.
Right then, you might want to try it out on the tool above to see other sequences.
GNC has been fixed. The digit is now clustered in the process.