The term 'HIGH NUMBER' can be solved by two crossword solutions: FIVE (4 letters) and EXPONENT (8 letters). FIVE is a cardinal NUMBER that comes after four and before six. It is the smallest prime NUMBER and is often used to represent the quantity of five items. EXPONENT is a mathematical term that refers to the power or index of a NUMBER, variable, or expression. It is usually represented by a superscripted NUMBER or letter, such as 2^3 or x^2.