I'm trying to learn Q notation but I don't understand why 1.01 in the Q2 number format equals -0.75. How is that calculation done? I can understand that 1.1 equals -0.5 because the leading 1 means the number is negative and the first digit after the binary point is 1 which means 1*2^(-1) which is 0.5 and therefore the number is -0.5. Similarly, 1.01 should equal -0.25 and not -0.75.

It is 1.11 which is -0.75 or what is my mistake?

  • 4
    $\begingroup$ What do you mean by Q2? I am only familiar with Qm.n format: en.wikipedia.org/wiki/Q_(number_format) $\endgroup$ – Atul Ingle Sep 25 '17 at 18:45
  • 3
    $\begingroup$ @AtulIngle : that page says m. (optional, assumed to be zero or one) so I'm assuming the format is Q1.2? $\endgroup$ – Peter K. Sep 25 '17 at 19:09

$$1\times (-1)+0\times2^{-1}+1\times2^{-2}=-0.75$$


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.