What notation is it called when a number is represented as a series of additions, for example:
124 = 100 + 20 + 4
This is a very simple question obviously but I don't remember what it's called! Thanks.
EDIT:
The reason I ask this question is for programming reasons. I want to take a value, such as 124, and create a list of variables (100, 20, 4) from it, so I wanted to know what that operation/ notation or whatever was called. I hope this helps you narrow down the possible correct ideas.
Seeing the way you wrote it, I thought of basis. A natural number $a$, written in base $b$ (also natural), is denoted by: $$a =(a_na_{n-1}\ldots a_1 a_0)_b = a_nb^n + a_{n - 1}b^{n-1} + \ldots a_1b + a_0$$
where $0 \leq a_i < b$. For example, when we write stuff like $124$ or $1675$ or $223$, we actually mean $$(124)_{10} = 1 \times 10^2 + 2 \times 10 + 4$$ In computer science, people often use base $2$, for example, consider the number $12 = (12)_{10} $. We have $(12)_{10} = (1100)_2 = 1 \times 2^3 + 1 \times 2^2 + 0 \times 2 + 0 = 12$.
If we have a base greater than $10$, we start using letters to represent the new algarisms. For example, in base $12$, we let $a = 11$ and $b = 12$, and we get numbers like $(a43b)_{12}, (bb214a4)_{12}$, etc.