When the number $$789678567456$$ is added to the number $$987876765654$$, how many digits does the sum have? 
Overseas Competition->Knowledge Point->Calculation Modules->Whole Numbers->Calculation of Multi-digit Numbers
The number $$789678567456$$ is added to the number $$987876765654$$.  Since we carry a $$1$$ when adding the left-most digits, the sum has $$12+1$$ digits. 