The series "Doodling in Math Class" on Youtube shows you different ways of looking at different mathematical concepts.

This article is a great example that the focus shouldn't just be on the test scores, but that the effort the students' make is crucial. It shows that, once again, the input reflects in the output.

An animation regarding prime and composite numbers. It demonstrates the Sieve of Erastothenes which is a method/algorithm for finding prime numbers.

Just an idea when teaching kids about axes of symmetry. It might make them more invested in the lesson.

Victor Borge demonstrates what the English language might be like if it followed the economy's pattern of inflation. It's highly amusing!

This website is an incredible collection of applet type things that gets students to interact. I've used it mostly with statistics (coin flipping, dice, spinners, etc.) and geometry. The students can discover things for themselves.