(In reply to possible way - spoiler
by Ady TZIDON)
"It is a simple calculator that can do one binary operation at a time."
Given the above statement, the broken calculator would require the equal key pressed for each binary operation. Assuming that the initial default value in memory is zero and is not counted as one of the two operands in the operation -7/7, the number of keystrokes required for your proffered expression, with the appropriate equals keystrokes, would be 20: -7/7 = +7 = +7 = +7 = +7 = +7 =.
Posted by Dej Mar
on 2013-07-31 12:33:42