Thanks to Pete for the link on what the question means. I was misled by the other responses.
Here are two thoughts:
i. What is the square root of 14? Well, it's between 3 and 4. Then we can do better by taking the average of 3 and 14/3. Then we can repeat this and do even better.
ii. Take the Fibonnaci sequence 1,1,2,3,5,8,13,... Take ratios of successive terms 1/1,1/2,2/3,3/5,5/8,8/13,... then these are approximations to the "golden ratio".
A personal anecdote: My daughter is 11 yrs old, bright and interested in maths. I tried i. on her and drew a blank look. I conclude from this that either it is a mistake to teach your own children or that she was not ready for this.