On Start of layout:
-Loop " " from 0 to 15:
--Add 9x10^loopindex to variable
I am getting 10000000000000000 (length is 17) as a result instead of 9999999999999999 (length is 16). I assume it has to do with base but I can't figure out how to get the correct value. I get accurate results if looped less than 16 times though. The expected results should have as many 9s equal to how many times it loops.
For my project I don't think many users will be entering more than a 15 digit number. I may just limit how many characters can be entered or I may work around the limit. There will still be a limit if I worked around it but it will be a lot higher than 15 digits.
Also when I changed the title of the post so it will be more accurate for other people and so others can learn from it too.
Also a ^ is called a caret symbol.
A solution is in this c3p, at least for multiplication, addition and exponents. I feel most people won't need it though and it will probably be better to use 'Add Script' and BigInt than to manually do it as I did.
The C3P has a few examples on how to do a few specific things that most people won't need. Be sure to disable all groups except for the one you are looking at.