Tesco Direct have up to 60% off Children's Educational Books at the moment, and prices start from as little as £1.99, and most have free delivery too!
There's a good range of Maths and English Workbooks, most with at least 50% off including Collins and Letts workbooks.
Workbooks like these are ideal for additional practice at home to reinforce your child's learning, or to keep ideas and concepts fresh in their mind during the school holidays.
There's a really good mix including Phonics, Maths, English, fractions, multiplication and division, grammar and punctuation and more.
I used some similar workbooks with my eldest when he was in Reception and I found that they really helped with phonics and handwriting, so I'm going to get some of the early learning ones for my youngest. He's starting Nursery in September so some of the fun workbooks mixed in with his sticker books this summer might help prepare him for big school.