In mathematics, there is relatively little that can be learned as facts. However, before you commit the sin of claiming that maths needs no revision, you need to have fixed the techniques into your mind, moving the learning from short term to longer term memory. These sheets bounce between topics, sometimes showing connections between those topics, but usually just reminding you of skills I think you should remember.
The really bad news? Maths is a cumulative subject: we use previous knowledge (all the time) to build up new ideas and techniques. The people who steadily slip down the system (top set not included) have generally lost (or not gained initially) skills from previous lessons. Which is one reason we spend so much time fixing your arithmetic - if you can’t do that……
I have put load of stuff in the ‘General’ section. Much of this could be practised, some of it could be learned. For GCSE there is a lot of sense in learning some of the conversion numbers, a mile = 1609.344 metres, 25.4mm = 1 inch, 454g = 1lb (a pound, more accurately 453.6g), and so on. That will steadily change, I expect. Knowing that a hectare = 100² m² is something I’d assume, but knowing an acre in m² would be unusual (most of us would look it up, some of us would work it out). I’d assume you know a ton and a tonne are about the same and I’d expect my classes to know a ton in terms of a tonne and that the difference is a small suitcase of weight (16kg, a pile of marking).
1 acre = 4840 yd² = 4840 x (36x25.4)² m² = 4046.86m²
1 ton = 2240 lbs, 1 tonne = 2204.6lbs; 1 ton = 1016.047 kg (≈2240/2.2.046)
