In many parts of the world, Pi Day is celebrated on March 14 (3.14), but because of the day-month ordering of dates in Australia, and because March is very close to the start of the academic year, Australians prefer to celebrate Pi (Approximation) Day on 22 July (22/7). Thirty-eight Year 8 students (aged 13-14 years) from two local high schools in Canberra, Australia, joined ESTeM Maths and Education staff on July 22, 2014, to celebrate Pi Day. This article describes the activities in which the students participated during the Pi Day celebration. The organizers of the activities selected six activities that met a combined criteria of feasibility, pedagogical soundness, and pedagogical appropriateness for the Australian school system. Time constraints were a significant factor in selecting activities. The students participated in the following activities: (1) measuring the circumference of the Earth using the length of a shadow at midday at two locations on the same longitude; (2) recording the diameter and circumference of household objects with a circular cross-section through the use of a variety of instruments and procedures; (3) working on a "History of p" activity sheet; (4) making Pi bracelets that indicate the digits of p, in order; (5) observing a demonstration of how the value of p can be approximated by the area of polygons with ever-increasing numbers of sides; and (6) following carefully devised p-trails across the campus. The article includes an evaluation of the data collected from both the students and the pre-service teacher education students on the activities undertaken, as well as reflections on the Pi Day activities.