Humphrey Carpenter 
Mr Majeika and the School Play [EPUB ebook] 

‘I really am quite useless as a wizard.’But Class Three thinks Mr Majeika is an excellent wizard, particularly when his spells go wrong! First Hamish Bigmore ends up on TV, then a real giant appears in the school play. And finally Mr Majeika gets the whole class lost on a magic carpet! There’s always an adventure with Mr Majeika around…