其它
When Xiao Dong did the subtraction equation, he saw the minuend as $$90$$ instead of $$75$$, and the difference he got was $$55$$. The correct result should be~\uline{~~~~~~~~~~}~. 
Overseas Competition->Knowledge Point->Calculation Modules
Wrong: $$90 - A = 55$$ -\/-\textgreater{} $$A=90-55=35$$  Correct: $$75 - 35 = 40$$ 