Number representation and calculations

Question

Subtract

1001₂

  110₂

             

Answer 1

Subtraction in binary is like subtraction in decimal:  borrow from the next higher digit when necessary.

    1 0 0 1₂
 -    1 1 0₂

------------

     .......1₂

 

 

  [moving right to left from second position, borrow, borrow making 0  1  10  ]

     0  ^{1  1}0  1₂     

 -      1   1   0₂

----------------

     0  0  1  1₂

 

Answer 2

We can work the two number in base 10 and subtract and go back to base 2.

1001₂= 1x2³+0x2²+0x2¹+1x2⁰=9

 

110₂=1x2²+1x2¹+0x2⁰=6

 

1001₂ - 110₂ = 9 - 6 =3 = 11₂