Weird attack bonuses (+8/+3 to hit)

[Philawallafox]

I'm a fairly noob GM and I'm leading a group through Rise of the Runelords in pathfinder. One of my players has a dwarf fighter with a battle axe which is giving me some weird attack roll bonuses. They have the "Two-Weapon Fighting" and "Double Slice" feats and for her attack role she has +8/+3 to hit. I don't know why it is representing it as a fraction, and I don't know how to test it in app, and I don't know how to look at the formula being used to get to that point so I can backwards engineer it, and I don't know where else to go. Please help.