You'd think that the reading for this would consist of the on'yomi readings, but human body parts (hand) do funny things to words. In this case, it's the kun'yomi readings of both the kanji. You should know the kun'yomi reading for 切 and 手 from the previous levels, meaning you should be able to remember the reading for this word fairly easily. Watch out for the small っ, though.
Then I’m going to go to the post office and buy stamps.
That foreigner bought 10,000 postage stamps.
Since I lost her, I've lost interest in stamp collecting.