Calculator trick

 Thanks dear Rahul for your good advice. After referring my book I came to the following conclusion. You intend to calculate log of 5.678954 to the base 2. So dear please do the following on your calculator, Press 2 then sq. root 12 times then - 1 then M+. Then press 5.678954 then sq. root 12 times then - 1 then divided by MRC = gives the solution. Thanks for your query. Future queries are most welcome. I will try to answer them after referring my book.