3 replies to this topic

[tman_ndsu08]

I'm trying to figure out how to multiply by a binary number by 0.8 if you can only add numbers to it and shift it left or right once at a time.

[tman_ndsu08]

Nevermind, my instructor is a complete tool.

His solution is that .8 is approx. equal to .75 so we should divide the number by 2 and divide it by 4, then add those together.

[Crane]

That doesn't make a lot of sense to me. .8 = .75? How is that possible? 3/4 = .75 but not .8.

[tman_ndsu08]

It's approximately equal, according to him.


I don't think it's possible to multiply by .8 if you can only shift right (divide by 2), shift left (multiply by 2), and add.


Just fyi, I'm using a PIC so there is no floating point operation.