Signa and Planck
The basic token (coin) on Signum is called Signa (Ticker: SIGNA). One Signa can be divided into up to eight decimals places. The smallest possible unit is called Planck, i.e.
1 Planck = 0.00000001 Signa (1^10-8) 1 Signa = 100,000,000 Planck
The Node HTTP API always returns the values in Planck, and their fields are always denominated with the suffix NQT. See an example here
To facilitate the calculations SignumJS provides the value object calls Amount and allows to convert and calculate between Signa and Planck.
Javascript is pretty bad at numeric precision, i.e. the maximum integer number is 2^53-1 and has infamous precision on floating point numbers. SignumJS uses bignumber.js to guarantee precise calculations. This is the reason you should always use Amount (and ChainValue) when calculating numbers