First of all, we start with the input 
Then we double it: 
Then we add 5 to this result: 
And this is the output: 
Its 30, i multiplied 6x5 and got 30 so im sure its the answer
Answer:
21
Step-by-step explanation:
Hi!to calculate a square root without a calculator is to see if you can get to that whole number by squaring smaller numbers,or multiplying a smaller number by it self.