13yo losing stuff all the time, help!

[forgettingtoremember]

Copied from my post in the Teens section as I didn't get any replies there...

DS is 13 and in yr8.
I'm ashamed to say I got angry with him earlier when he told me he'd lost the new calculator I bought him 2 weeks ago to replace one that he broke, which I'd bought him to replace one he'd lost
I checked his bag, he had 1 pen in it. That was it. So he's lost a handful of pens since the start of term.
He "can't even remember" having a ruler or highlighters (he did have).
Thing is he doesn't really seem to care. I need to tell him to look in lost property/ retrace his steps etc. He wouldn't do it if his own accord.
He hates telling me that he's lost stuff, but makes no effort to look after stuff he does have nor to locate stuff thats gone missing. It's completely out of sight out of mind.
I ordered him a whole load of new stuff from Amazon tonight, and used his card to pay for it. I'm not paying for things any more.
What else can I do?? I can't follow him around school.
He's a lovely kid, he hasn't turned into a grumpy teen just yet. But he's bloody useless with his stuff.
Help!

From start of High School I had the 50% rule. I buy everything 100% once at start of year anything lost/broken will cost you 50% of replacement. It soon seemed to focus his mind on not loosing stuff and after having to work 3 days for no money to pay off a screen repair bill made him not break things so much. He still is the worse at loosing stuff but as he's an adult now not my problem.

I don't have an answer, but are you sure he is definitely losing stuff and not having it taken off him or lending stuff to people anf not getting it back?

Assuming you have to move to new classrooms each time after a lesson, and pack stuff away, how does it get lost? Broken is a bit more understandle periodically I think.