Number of Squares in a Square

n

10

1+4+9+16+25+36+49+64+81+100

=

385

How many squares can you find in the grid? This Demonstration shows how these three things are related: the concept of a square number, a visual puzzle, and the formula for the sum of the first

n

square numbers, which is

1

6

n(n+1)(2n+1)

.