For those tuning in late, here's how I added my AirPods to an iPad 3 running 9.3.5:
How to Pair AirPods to an iPhone: 13 Steps - wikiHow
The iOS will tell you to update (10.2 minimum) but that's for the auto-pairing feature. You can ignore that. When your AirPods show up in the device column (on the right side) it will say Connected or Not Connected. If the latter, just tap the i and you're good to go.