Step 1 : Go to School Calendar at school website or Click Here 
Step 2 : Click “ + Google Calendar”  to add Calendar to your google account

Step 3 :  A list of Calendars will pop up for you , add calendar you would like to sync with your calendar.

Step 4 : List of Calendar will show up under Other Calendars 

Step 5 : Adding your Other Calendars to your Ipad / Iphone is simple can be done by go to the following link or click Here
Step 6: Select calendar which you would like to sync with your iPad , and after you finalize click save
Give it a minute to sync and you’ll be ready to go , you might need to reset your iPad or iPhone .