Computers use binary math, here is how it works.

Regular decimal numbers use 10 symbols, the common numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

Binary math uses only two symbols, 0 and 1.

We use LEDs to represent 0 and 1. "0" is represented by "OFF" and "1" is represented by "ON".

We are creating "4 bit" binary numbers, represented by 4 LEDs. Each LED location has a "value".

The LED on the extreme right has the value 1, the next LED's value is 2, then 4 and 8 at the left end.

To determine the decimal value of a binary number add up the values of the "ON" LEDs (remember OFF is "0").

For instance 5 = 4 + 1.

Here is a table that shows some of the decimal values for a 4 bit number.

Regular decimal numbers use 10 symbols, the common numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

Binary math uses only two symbols, 0 and 1.

We use LEDs to represent 0 and 1. "0" is represented by "OFF" and "1" is represented by "ON".

We are creating "4 bit" binary numbers, represented by 4 LEDs. Each LED location has a "value".

The LED on the extreme right has the value 1, the next LED's value is 2, then 4 and 8 at the left end.

To determine the decimal value of a binary number add up the values of the "ON" LEDs (remember OFF is "0").

For instance 5 = 4 + 1.

Here is a table that shows some of the decimal values for a 4 bit number.