The term 'A VERY SMALL QUANTITY' can be expressed in two words with four and five letters respectively: IOTA and TRACE. IOTA is a Greek letter that is often used to represent a very small quantity, such as a tiny amount of something. TRACE is a verb meaning to find or follow the course of something, but it can also be used to describe a very small amount of something. Therefore, both IOTA and TRACE can be used to express the idea of a very small quantity.