Definitely. You could do something like Double Maths, Physics, Chemistry and Economics, and if you don't feel like doing that much in the upper sixth then you could easily drop something you don't like. (It gets a bit tougher with A2s.) 5ASs including Double Maths is a manageable combination. 4As is better than 2As and 3Bs, but 5As is better than either of those, and you also have the benefit of increased flexibility with your options. If you want to do Maths or another Science subject, but are unsure about which specific science to choose, then Double Maths, Physics and Chemistry is definitely advantageous compared to Double Maths and Chemistry in my opinion, as you'll have access to Physics and Engineering degrees.