Page 28 - TP_iPlus_V2.1_Class7
P. 28

For example, let us subtract the binary number (111)  from (1000) .
                                                                         2             2
                          X           Y                   X – Y
                                                                                          1     1
                          0           0                 0 – 0 = 0                                        _____
                                                                                     0  (10)  (10)  (10)       Borrow
                                                        0 – 1 = 1
                          0           1
                                             (borrow 1, so that 10 – 1 = 1)          1    0    0     0
                          1           0                 1 – 0 = 1                 –       1    1     1

                          1           1                 1 – 1 = 0                    0    0    0     1




                     To Sum Up


                          The smallest piece of data that can be recognised and used by the computer is known
                         as a bit or a binary digit.
                          A number system is a way to express quantities used for counting, comparing amounts,
                         performing calculations and representing values.

                           A number system made up of ten symbols, 0 to 9, is known as the decimal number
                         system.

                          A number system made up of only two symbols, 0 and 1, is known as the binary
                         number system.
                           A number system made up of eight symbols, 0 to 7, is known as the octal number
                         system.
                           A number system made up of sixteen symbols, 0 to 9 and A to F, is known as the
                         hexadecimal number system.





                                                            Exercise


                                                        Section A (Objective)
                  A.  Tick (3) the correct option.

                      1.  Which of the following is not the correct name for the number 0?
                         a. Nought                                       b. Naught

                         c. Zilch                                        d. Unity


                      2.  A single binary digit is called a ................................ .
                         a. Byte                                         b. Bit

                         c. Word                                         d. All of these









                    26
                         iPlus (Ver. 2.1)-VII
   23   24   25   26   27   28   29   30   31   32   33