When counting squares in a grid, don’t stop at the smallest boxes; the bigger ones are hiding too. The rule is simple: In an n × n grid—where n is the number of squares both horizontally and ...

If you notice that the first term is a perfect square, and the second term is a perfect square, and you have a negative here, we can say that it is "the difference of two squares." What we want to do ...

The number 9 can be written as a difference of two squares as 3 2 – 0 2 = 9 – 0 = 9. Can you find a different way to express it as the difference of two squares? Which numbers between 1 and 30 can be ...