Hi, I like this project,
Most I like its functional style compared to BigNumber.js, and this library is much smaller.

It would be interesting to me, if we could make it an NPM module.
I would also like to add some tests to increase the trust in this module.

I found this project, because recently our database administrator changed some field in mysql from int to long. In first place it was ok to handle the field as string, but I have to compute those values.

can you give me some thoughts, where you want to go with this project?