[robot_no_421]

3 is the following function: 3 == lambda x: 3*x

But I think that the technical, mathematical way to think about it is:

The monoid of linear functions L:R->R is isomorphic to the monoid (R, *)

Meaning, the structure of 1x1 matrices under multiplication is exactly the same as the structure of real numbers under multiplication.

[contravariant]

Importantly matrix multiplication is the same as function composition of the linear functions, hence the analogy to functions that multiply by a factor.

Seems trivial but among other things it implies associativity, which is not quite trivial for larger matrices.