I have 2 questions here.
What is the most effective and easy way of calculating square roots in your head to an accuracy of 1 decimal point? This would need to work with at least two digit, non-perfect squares and would have to be doable mentally.
- How would the method work?
Is one decimal place accurate enough for all intents and purposes that you may come across in average math? When would you need more precision?
I am curious because often times in school, I would spend time with paper and pencil, working out approximations for non-perfect squares, it would help if I could get an approximation quicker.
Edit: Please ensure that the method is easy to understand, and to do mentally for a student in grades 8 and above. I don't want to be just memorizing formulas without understanding how they work, I think it would be beneficial for anyone browsing this question.