Since it is super-urgent, it is probably a test or quiz. I should not have answered the question. I will help by giving you an example. You will need to work it out using a calculator. This is the best I can do.
Well, you just divide 7056 by a guess number x.
Take the average of x and the quotient (result of division) and repeat again.
Example:
Find square-root of 700, with an initial guess of x=27.
The quotient is 25.92592592592592
Taking average of 25.92592592592592 and 27 gives 26.46296296296296.
Using new guess x=26.46296296296296 and repeat the same process, we get 26.45751367182438
Using the new guess x=26.45751367182438 and repeat the same process, we get 26.45751311064591 which is accurate to 13 places after the decimal.
If it is not clear, try finding square-root of 625 and the final answer should be 25 (exactly) after three or four repetitions.
Feel free to ask for more explanations.