If your school is a registered institution with Apple, the iPad version can be purchased through Apple with an educational discount of 10%.
Standard retail copies of the game can be used for educational purposes. If you're interested in purchasing 10 copies or more for your school, please contact me at media -at- this domain for a 10% bulk discount.
Educational institutions are permitted to install and use one legally-obtained copy of the game per seat. School-owned devices can contain the game, which can then be played by more than one student. Student-owned devices require separate copies.