When you have a possibility of choosing the easiest and fastest method when solving an equation, your flexibility and creativity are stimulated. In this book I introduce a new formula for quadratic equations and a new method for factorising polynomials. With this method all kinds of equations with rational numbers can be solved easier and faster than with any other formula or method. But in order to solve quadratic equations containing irrational'numbers, e.g. pi, a formula must be used. A comparative test showed that quadratic equations were solved much faster by using this new formula compared to the so called pq-formula. In addition all these equations could be solved by mere mental arithmetic. Some equations containing rational numbers can even be solved by mere mental arithmetic without using pen and paper.