A blog for enthusiastic math-lovers!

Archive for September, 2011

Dealing with Intimidating Looking Problems

Topic 1: Summations

When I was younger, I always believed that working with problems that looked short and that did not have many scary symbols was easier than dealing with long, complex looking questions. Concepts which especially intimidated me were summations and floor functions. Just by the look of them, they seem s like a mess. However, in reality there are problems in those topics that are very simple!

In summations, often times a concept called telescoping comes into play. Telescoping is when you are able to cancel out most terms in the summation. In summations it is also helpful to sometimes reorganize your problem.

Summations problems come in all different shapes and sizes. The following problem is #14 on the AIME which I spoke about in my previous post.

For each positive integer n, let f(n) =\sum_{k = 1}^{100}\lfloor\log_{10}(kn)\rfloor . Find the largest value of n for which f(n)\le 300 .

Note: \lfloor x\rfloor is the greatest integer less than or equal to.

Please comment if you have any ideas for creative solutions! I will give hints for this problem in later posts! Have fun with this problem!

Also good luck to all of the girls participating in the Math Prize for Girls next weekend!

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Welcome!

Welcome to the wonderful world of mathematics problem solving!

Often times, mathematics problems seem like enormous messes. There are certain questions that we, problem solvers, encounter that do not seem to ever terminate. However, with the knowledge of a few special tricks they fall to pieces and become very elementary. This blog is for people who are interested in messy, difficult-looking, yet very interesting problems. They are not your typical high-school math, “plug and chug” questions. They delve deeper into the concepts that you learn in high-school mathematics. This blog creates an opportunity for you to witness creative solutions and interact with others!

With my personal experience, I have encountered many challenging questions. However, even now I still get discouraged when a problem seems frightening or very messy at first sight. The first time that I took the AIME, question number 14, was a relatively simple problem. However, since it was #14 (out of 15 questions on the AIME contest) and I was still relatively inexperienced, I barely even looked at this problem when I took the contest. The problem seemed challenging with “scary summations”. However, as it turned out, this problem was not bad at all. When I got home, I solved it in about five minutes. Since then, I have been very cautious when it came to “messy-looking” problems because I didn’t want to miss such a chance again.

This blog is for people like me who seek an extension to their mathematics knowledge and the confidence to approach such “scary, messy” problems. I will periodically present tough problems, and explain their solutions showing how the mess turns into a simple, beautiful work of art.

Come join the fun!

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