title: Booths algorithm and right shift
body: <p>I know the working of booths algorithm.</p>
  
  <p>Suppose we have multiplicand M = 01011</p>
  
  <p>and multiplier Q = 01110</p>
  
  <p>We can write Q as (2^4 - 2^1).</p>
  
  <p>So multiplication reduces to 2^4(M) + 2(-M)</p>
  
  <p>Now booths algorithm rules are:-</p>
  
  <p>If Q = 0 and Q(-1)=0 then do arithmetic right shift.</p>
  
  <p>If Q = 1 and Q(-1)=0 then do A-M and arithmetic right shift.</p>
  
  <p>If Q = 0 and Q(-1)=1 then do A+M and arithmetic right shift.</p>
  
  <p>If Q = 1 and Q(-1)=1 then do arithmetic right shift.</p>
  
  <p>Here A is initialized to 00000 and Q(-1) is initialized to 0.</p>
  
  <p>If we see the algorithm then in every step we do right shifting. But as per the calculation shown above which is 2^4(M) + 2(-M) we multiply by 16 and 2 which requires left shift.</p>
  
  <p>So how is booths algorithm working with right shift ? I am not able to get the intuition behind it.</p>