How much is A+B+C+D?

Rem: XY denotes 10*X+Y

I fully admit that there are some flaws in this puzzle, but none of them IMHO justifies the “1” rating   given by one of the solvers.

The right points in time to address the issues of approximation, order of operations, the status of “leading zero” and some others issues  were either   while the puzzle was on the reviewing board   or immediately upon publishing, asking for clarifications   to provide an unambiguous text understandable by other solvers.

Approximation: I did not find the right symbol and copied from unrelated source the congruence sign.  Sorry.
  As to what is “approximate” (i.e. what percentage, or what absolute value of the difference) any  definition would include the exact value.

Leading zeros:  to the best of my knowledge in all previous puzzles on Perplexus the exclusion of leading zero is explicitly stated, so there is no need to specify that  05 could be accepted.

PEMDAS is an acronym for OOO,  along with PEMA, BOMDAS, BODMAS and others but it has   so many exceptions and no-clear-cut interpretations ( –a^n, ½*a,  23-11+5,  2^3^4  etc )  that should not be considered at all in  operations  non related to basic arithmetic (like temperature conversion).
IMHO  it is for kids, not for mathematicians.

My intention was   (2*CD) Celsius converts to DC Fahrenheit. Whoever had doubt could try to solve two puzzles at the price of one. Big deal.

Since the puzzle was created bottom-up I was aware only of one answer for A+B+C+D.

This   happened many times in the past and usually was properly addressed by the solvers.

Whoever reads my remarks is invited to express his view re the intrinsic value of the puzzle by posting his comments or his rating.

Your feedback is appreciated.