Welcome to the Bunnings Workshop community @nurse. It's sensational to have you join us, and many thanks for your question about tile quantities.
If you multiply 305mm x 305mm, you get 93,025 mm2. 7000mm x 4000mm is 28,000,000mm2. 28,000,000 divided by 93,025 is 301. There are 11 tiles in each box, so you'd need 28 boxes.
After working that out, I realised that the product states there is 1m2 in each box, and you have 28m2, so I guess my math is correct that you need 28 boxes. 😁
Hope that helps!
Please let me know if you have further questions.
Mitchell
