What do you call the additional paper used during exam and homework?

When doing exams or homework, one might need some extra paper to make a rough sketch, before writing his solution into another paper that must be turned in. The extra paper does not need to be turned in.

What is that extra paper called? Would "draft paper" fit?

"Scrap paper" or "scratch paper" are common terms for this, which may vary in English-speaking areas as this discussion shows.

The term scrap paper is very widely used and understood in schools and offices throughout the UK.

The alternative term scratch paper would be understood because of the widespread American influence on the language here...

Some American participants also used "scrap paper" depending on region, but might say "scratch pad"; I don't think there is a clear division in usage.

It's interesting to note that US-based exams like the GRE and SAT call it "scratch paper" but there are plenty of discussions in search results about "scrap paper" at these exams.

"Scratch" paper is the usage I'm familiar with. I can't really find a derivation for it, but Google Ngrams has it appearing in this sense somewhere around 1890 or so.

I have always heard that paper refered to as "scrap paper". I believe this refers to what should be done with the paper after its use.

Here is some additional research into the origin.

Originally called a scrap of paper