On Fri, Sep 28, 2012 at 9:36 PM, Robert Hansen <firstname.lastname@example.org>
a^2 - (a-1)^2 = a^2 - (a^2 - 2a + 1) = 2a - 1 = 13.04822...
This is a very good point, work the algebra FIRST. I wonder how many algebra teachers are even capable of concocting such a problem? Working backwards and making sure that 2*a doesn't require any more than single digit math (no digit greater than 4). I have to think about this. This works well with large integers as well, with the same condition on the digits.
Lou, what do you say to problems like this with regards to our prior art discussion?
Ha, calculators are allowed. Calculators with 70 digits of precision I suppose.:)