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Has any heard of the Happy Face method for Square Roots?

I heard of this method called the happy face method from a math teacher. Does anyway happen to understand the concept of this because I don't. Here is an Example- 3.60 rounded to 3.6 3_/------------------ 13. 00 00 _- 9______ 06 -| 4 00 | -396 720 _ |4 00 |- 0 400 I really don't get this!

Public Comments

1. I can't quite make out what it is (Yahoo seems to strip out the spacing that would be needed for that to be human-readable), but it might be the methods described in the URLs below. The idea is roughly to work one digit at a time from largest down. You can actually compute square roots with no "method" at all in this way. (Example, for the square root of 123: since 11^2 is 121 and 12^2 is larger than 123, it's 11.something. I see that 11.1^2 is already too big, so it is 11.0something. Calculating 11.01^2, 11.02^2, and so on I can see that 11.09^2 is still less than 123, so it is 11.09something. If I do square roots this way, I need to compute up to 10 products to get an additional digit of the square root--- so it's not a very good method--- but it is a method.) The method outlined in the webpages below is an enlightened version of the "guess and check" process I just outlined. It uses long division like symbolism to keep track of groups of digits and a a little bit of algebra to eliminate most of the guesswork needed at each stage to get the next digit. But it amounts to almost exactly the same idea. Don't worry too much about not "getting" the long-division-like way the calculation is presented. It isn't meant to explain anything--- it's just a way of organizing the calculations for a clever method, so that anybody can come along and use the clever method without thinking. It's just like long division in this respect: if you learn to do it in a certain organized way, you don't need to think about "what" you are doing, you can just follow the rules of long division and calculate things. (Understanding why the procedure does what it is claimed to do is a completely separate issue.)