How to store cryptocurrency balance without causing floating point errors in ruby rails

Question

I'm creating a rails app where users will have an account balance in Ethereum and possibly other cryptocurrencies. Currently, I am storing the user's balance as afloat. This, however, is a really bad approach as cryptocurrencies are usually divisible down to 8 digits so any floating-point error will cause a huge loss/gain in funds. How can I store the user's balance (what datatype should I use) so as to not cause floating-point errors? Thanks

Answer 1

 I suggest storing the values as integers. Just multiply the currency values by a million or so when you store them and convert them as needed in your application.Ruby has a special class for this:

BigDecimal -> https://ruby-doc.org/stdlib-2.4.0/libdoc/bigdecimal/rdoc/BigDecimal.html