The term 'It's Elementary' can be solved by two crossword solutions: ATOM (4 letters) and GRADEONE (8 letters). ATOM is a term used to describe the smallest particle of an element that still retains its chemical properties. GRADEONE is a term used to describe the first year of elementary school. Both terms are related to the phrase 'It's Elementary' which is often used to describe something that is simple or easy to understand.