Students from 6^th grade who are keen on mathematics from “Ivan Vazov” Secondary School celebrated the day of the mathematical constant PI on 14 March, 2014. They have prepared the kite with a long tail which consisted the numbers after 3,14 but the tail was not so long as the constant. The students displayed the designs in an exhibition of angular and spindling bodies, for which construction they used the constant PI. With this exhibition they rearranged the school agenda and showed that everything is based on the mathematics.