How to properly describe the problem statement?

Question

We are given a set of 4 numbers = [1, 2, 3, 4]. If I want to write (1, 2), (2, 3), (3, 4), I would say: write every two consecutive elements in the set.

But if I want to write (1, 2), (3, 4), how can I say that?

Answer 1

You could say:

Split the set in pairs.

Someone could argue that (1, 4), (2, 3) is such a split, in that case

Split the set in pairs of consecutive numbers.

should work.