I have been receiving a growing interest for textbook for the math classes. As I had mentioned in the blog before Oxford International Maths for Cambridge Secondary 1 (Cambridge Checkpoint and Beyond) is the textbook that I refer and use in my classes with some other books.
Although not compulsory, Grade 7 students are recommended to buy this book. You can order it from Amazon. The link for Amazon is here.
The book has a lot of exercises and it will be helpful to practice from there.
Please feel free to email me if you have any questions.
PS. There is also a homework book, but it is quite expensive, since I give photocopies from that, you do not need to buy the homework book.