# MSD and LSD

When you’re determining the MSD and LSD for binary numbers, use the same guidelines you used with the decimal system.

As you read from left to right, the first nonzero digit you encounter is the MSD, and the last nonzero digit is the LSD.

If the number is a whole number, then the first digit to the left of the radix point is the LSD.

Here, as in the decimal system, the MSD is the digit that will have the most effect on the number; the LSD is the digit that will have the least effect on the number.

The two numerals of the binary system (1 and 0) can easily be represented by many electrical or electronic devices. For example, 12 may be indicated when a device is active (on), and 02 may be indicated when a device is nonactive (off).

Binary-Example.

Look at the preceding picture above. It illustrates a very simple binary counting device. Notice that 12 is indicated by a lighted lamp and 02 is indicated by an unlighted lamp. The reverse will work equally well. The unlighted state of the lamp can be used to represent a binary 1 condition, and the lighted state can represent the binary 0 condition.

Both methods are used in digital computer applications. Many other devices are used to represent binary conditions. They include switches, relays, diodes, transistors, and integrated circuits (ICs).