This Design Idea presents a method for fast integer multiplying and multiplying by fractions. What can you do when you lack access to a hardware multiplier or MAC (multiply/accumulate) function and ...

I. J. Schoenberg, On the Zeros of the Generating Functions of Multiply Positive Sequences and Functions, Annals of Mathematics, Vol. 62, No. 3 (Nov., 1955), pp. 447-471 ...

The “x3 circuit”, a nontrivial portion of the Pentium processor, is dedicated to multiplying a number by exactly three and contains more transistors than an entire Z80 microprocessor.