My Rang III pupils are naturally curious. We had a most enjoyable class making egg-timers using re-cycled plastic bottles and free flowing solid materials. The timer had to take 1 minute for all the sand to travel from one end of the timer to the other. Our pupils had great fun ensuring the egg timer was free standing and testing that it worked three times in a row. A lively discussion, estimation, problem solving and prediction took place. Congratulations to all on their wonderful experiments. Many thanks to Joe O’Reilly and Saoirse McNamara for all their help.