CHAPTER 3 Digital Systems Digital systems work with inputs, which are essentially just off/on signals, with the two signal levels represented by 0 and 1. These are termed binary digits. The number system used for everyday calculations is the denary or decimal system. This is based on the use of 10 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. With a number represented by this system, the digit position in the number indicates the weight attached to each digit, the weight increasing by a factor of 10 as we proceed from right to left. Hence we have: 10 3 Thousands 1000 10 2 Hundreds 100 10 1 Tens 10 10 0 Units 1 Denary Thus if we have the denary number 1234, we have 1 with a place value of 10 3 , 2 with a place value of 10 2 , 3 with a place value of 10 1 , and 4 with a place value of 10 0 . Counting can,