 Binary logarithms also occur in the exponents of the time bounds for some divide and conquer algorithms , such as the <unk> algorithm for multiplying n @-@ bit numbers in time O ( <unk> 3 ) , and the Strassen algorithm for multiplying n × n matrices in time O ( <unk> 7 ) . The occurrence of binary logarithms in these running times can be explained by reference to the master theorem . 
