1-31Table 1-5. —Binary and Hexadecimal ComparisonUnit and NumberAs in each of the previous number systems, a unit stands for a single object.A number in the hex system is the symbol used to represent a unit or quantity. The Arabic numerals0 through 9 are used along with the first six letters of the alphabet. You have probably used letters in mathproblems to represent unknown quantities, but in the hex system A, B, C, D, E, and F, each have adefinite value as shown below: