Difference of Squares

The difference of squares is a fundamental algebraic identity: $x^2 - y^2 = (x - y)(x + y)$. This trick is easily recognizable and simplifies calculations involving the subtraction of two squared numbers.

For example, to calculate $54^2 - 55^2$, you can apply the formula:

$(54 - 55)(54 + 55) = (-1)(109) = -109$

This method is significantly faster than calculating each square individually and then subtracting.