20 worksheets of a similar style to that shown. Each worksheet is followed by a page with the answer on it. It can be used for starters, homework or class exercise. I ahve sued with Year 7 and also 6th form; with the latter a short amount of time makes it a challenge. It can be printed A4, with room for working around it or A5 size to stick in books. It also works well just shown on a whiteboard. For younger students, you could give them the answer at the end of the 1st or 2nd row to help them, if you choose (the answer page only gives the final answer though).