Binary Numbering: 1s, 2s, 4s, 8s (and so on) Digits

With decimal, the digits in a multidigit decimal number represent various powers of 10. The same kind of thing happens in binary, with the rightmost binary digit meaning the number of 1s (2⁰), the second from the right representing the number of 2s (2¹), the third from the right representing the number of 4s (2²), and so on.

Table B-2 shows the value associated with each digit (or column), with each being a consecutive power of 2, increasing from left to right. So, what does this really mean? Well, just like the decimal number 235 means (2*100) + (3*10) + (5*1) = 235, the binary number 11101011 means the following:

(1*128) + (1*64) + (1*32) + (0*16) + (1*8) + (0*4) + (1*2) + (1*1) = 235 decimal

If you add up the numbers, you actually get the number 235 in decimal. The numbers 235 (decimal) and 11101011 (binary) both represent the same number; they're just written in different formats.