What is the origin of the idiom "put two and two together" and when to use it?

The origin of the idiom "put two and two together" is not definitively known, but it likely stems from the basic mathematical principle of addition, where combining the numbers 2 and 2 results in 4. It is commonly used in situations where there are clues, hints, or pieces of evidence that, when combined, reveal a larger truth or understanding.