What are the names of the codes used in calculators?

Calculator uses binary operations in calculation in which only binary addition and binary subtraction operations are used. Algorithm does not use binary division and binary multiplication operations. Calculators have humane interface unit that converts Human understanding decimal digits (ie 12, 34 etc) in to machine understandable binary digits (ie "0" or "1"). For example decimal digit "2" is equal to binary digit "0000010" and decimal digit "3" is equal to binary digit "0000011" now addition of 2 and 3 is 5 that is obtained by binary addition operation "0000010 + 0000011"=>"0000101". Though this operation is OR logic operation and is simple for addition and subtraction but for large operation it is bersome to calculate final value. I request you to read book "Computer Design and Logic Operations" written by Mano.