A multiplication control system comprising a multiplying circuit to which a binary-coded multiplier and a binary-coded multiplicand are supplied, a leading 0/1 decoder which detects the number of significant digits in the binary-coded multiplier, a divider which divides the detected decoder output by a predetermined number, a selector into which an external constant is entered, a recursive control counter to which an output of the selector is supplied, an arithmetic unit which calculates the difference of outputs from said divider and said counter, a zero detector which detects the content "zero " of said recursive control counter, a shift circuit to which a product of said multiplying circuit controlled by the zero detector output is transmitted, and a multiplier which multiplies the output of said divider by a predetermined number and supplies the result to said shifter.