Quicker way? Hmm...

• When you multiply 11 by something, it basically equals to $$\text{that number} \times 10 + \text{that number}$$.
So it is that number plus that number 'shifted' 1 place to left.
So if that number is 121, it would look something like this:
121
+121
So it is $$\text{(hundreds)} + \text{(tens + hundreds)} + \text{(ones + tens)} + \text{(ones)}$$, which is the same as Pascal's triangle!
Then just clear up the mess and you get a number.