mathcounts notes

Proof :  2y = 2x + b (exterior angle = the sum of the other two interior angles) --- equation I y = x + a (same reasoning as above) -...

Counting Coins  Lots of similar questions appear on Mathcounts tests. Be careful when there are limits, for example, the sum of the coins d...

#24 2001 Mathcounts Sate Sprint Round: The number 4 can be written as a sum of one or more natural numbers in exactly five ways: 4, 3+1, 2 ...

Check out Mathcounts here, the best competition math program for middle school students. Download this year's Mathcounts handbook her...

These are some common sums that appear on Mathcounts often. \(1+2+3+\ldots +n=\dfrac {n\left( n+1\right) } {2}\)  \(2+4+6+\ldots .2n=n\l...