Idioms involving 'two'

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi,

Could you tell me what the sense of ‘two’ is in the following idioms:

  1. Put two and two together.
  2. Put the two together.

Thank you.

haihao

2

2 + 2

For example, to understand something (situation) clearly by interpreting separate facts together.

A bit another use: ‘As plain as two plus two make four.’
(Also see: en.wikipedia.org/wiki/Two_plus_two_make_five )