Subtracting hexadecimal numbers is not much different than subtracting decimal numbers once you understand what a hexadecimal number is. The hexadecimal system is based on the number 16 instead of the number 10 like the familiar decimal system.

**Understand how to count with hexadecimal numbers**Just as the decimal system has 10 digits, 0 through 9, the hexadecimal system has 16 digits. The 16 digits of hexadecimal are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E and F.

**Convert hexadecimal letters into decimal equivalents**When doing operations such as subtraction with hexadecimal numbers, think of the letters as equal to numbers, so A equals 10, B equals 11, C equals 12, D equals 13, E equals 14 and F equals 15.

**Line up numbers with more than one place, and subtract from right to left**For a problem with more than one digit, line the two numbers up just as in decimal subtraction, aligning the placeholder positions. For example, FF minus D1 is aligned into F minus 1 and F minus D. As with decimal subtraction problems, begin at the right. F minus 1 is the same as 15 minus 1 which equals 14, or E in the hexadecimal system. F minus D is the same as 15 minus 13, which equals 2. Therefore, FF minus D1 equals 2E.

**Borrow 16 from the next higher place when necessary**In decimal subtraction, when the number to be subtracted is greater than the number to be subtracted from, you solve by borrowing a 10 from the next higher place. In hexadecimal subtraction, you borrow a 16 instead. So for 26 minus 18, because 8 is greater than 6, you must borrow a 16 from the 2. Add the 16 to the 6. This gives you 22, from which the 8 is subtracted to equal 14, or E. Since you borrowed from the higher position, only 1 is left from which to subtract 1. In other words, 26 minus 18 is equal to E in the hexadecimal system, not 8 as it is in decimal.