How do I work with 16 digits numbers ?

hi

i need to make an app which get 2 number and it start from lower number and every tick add 1 to lower number until it get to the bigger number

like this :

lownumb < bignumb

repeat => add 1 to lownumb

but this numbers are 16 digits and it just work with 15 digits

(i can use numbers as a string then get right number which is not 9 and then add to that and if the last number is 9 then add to left number but i need a simple formula !)

Well 64 bit floating point numbers only keep track of 15-17 significant digits, so that would explain one part of it.

To get around it you could use two variable with say 10 digits a peace. Then when the second half is at 11 digits, remove the first digit and add one to the second half. Or something like that.