Since this word is made up of a single kanji, it's supposed to use the kun'yomi reading. But, there is no useful kun'yomi reading for this kanji, so even the single kanji vocab word version uses the on'yomi reading, which you've already learned!
I’ve watched this movie three and a half times.
There is only a month and a half left until the JLPT.
She is as cute as a half-cooked egg.