Look wot I winned in Shcool, mum! I got given Prize's!

This letter was pinned up in my local Tesco Metro. Here's a question Mr Headteacher, when are you going to teach the kids about the correct use of apostrophes?



I'm sure the kids loved their prize's.

I was also confused by the school motto on the letterhead, and I quote...

"Our Mission is to be the best I can be and proud I am me."

I'm all for motivating and building self-esteem into young people, but I also want them to be able to construct sentences that makes sense. How can 'our' mission be something 'I' do?