Besides using only base 10 representation, 1) all numbers are exact even if there are multiple representations. 2) because of 1), .1 + .2 = .3, eg, arithmetic follows the same rules you learned in school for 4 function arithmetic. 3) It supports upto 56-bit precise integer math without loss of precision. Look around YouTube for crockford talks about it. Usually they're JavaScript related. Or check dec64.com