Uses a single-linked list to represent a binary number. The decimal number 37 can be represented by the binary number 100101. This binary number can be shown as 2^5 + 2^2 + 2^0 = 37 where we are adding terms for those bits of the binary number that were 1, and each term is 2 raised to some power dependent on the bits position. Each term can be represented by a node in the linked list storing that bit’s position. So the above binary number could be represented by a linked list of (0)->(2)->(5). Does NOT store 0 bit terms.