In the decimal system, there are places for 1s, 10s, 100s, 1000s and so on. Each place goes up by 10 times the value of the place before it. With the binary system, the places are 1s, 2s, 4s, 8s, 16s, 32s, 64s, 128s and so on. Each place goes up by double the value of the place before it. The binary number 1010 has no 1s, one 2, no 4s and one 8. Adding the 2 and 8 together makes the number equal to 10 in decimal.
