1. A logarithm approximation method, comprising: (a) providing N-bit numbers c and d where N a positive integer and d is less than or equal to c; (b) extracting M-bit number m from said c where M is a positive integer less than N, said m aligned to the most significant non-zero bit of c; (c) extracting M-bit number n from said d, said n aligned to said m; (d) piecewise linearly approximating a logarithm of said m; (e) adjusting the approximation of step (d) by a table entry; (f) piecewise linearly approximating a logarithm of said n; (g) adjusting the approximation of step (f) by a table entry; and (h) approximating a logarithm of the quotient d/c by the difference of results of step (g) and step (e).