Addition and Subtraction of Numbers in Base 2 Numerals - JSS3 Mathematics Past Questions and Answers - page 2

    101

  + 110

  -----

  1011

Step-by-step:

1+0=1

0+1=1

1+1=10 (write 0, carry 1)

Write down the carry (1)

101+110=1011

    101

  + 110

  -----

   1011

+  011

  -----

   1100

Step-by-step:

1+1+1=11 (write 1, carry 1)

0+1+1=10 (write 0, carry 1)

1+1=10 (write 0, carry 1)

Write down the carry (1)

101+110+011=1100

    110

  - 101

  -----

    001

Step-by-step:

0−1 (borrow 1, becomes 10−1=1)

1−0=1

1−1=0

110−101=001

First, subtract 010 from 111:

    111

  - 010

  -----

    101

Next, subtract 001 from 101:

    101

  - 001

  -----

    100

111−010−001=100

    10

  x 11

  -----

    10    (10 * 1)

+ 10    (10 * 1 shifted one position to the left)

  -----

  110

Step-by-step:

10∗1=10

10∗1=10 (shifted one position to the left)

10×11=110

       100

    ------

11 | 1100

   - 110

    -----

      000

Step-by-step:

11 fits into 1100 starting from the second digit, 

so write 1 and subtract 110 from 1100, getting 000.

1100÷11=100