The term 'Decimal System' refers to a system of counting and measuring that uses the base 10. This system is used in many different areas, including mathematics, science, and finance. The two crossword solutions for this term are 'DEWEY' and 'TENS'. 'DEWEY' is a reference to Melvil Dewey, an American librarian who developed the Dewey Decimal System, which is a library classification system based on the decimal system. 'TENS' is a reference to the fact that the decimal system is based on the number 10, or tens.