Im y13 and I currently take maths, further maths, physics and geography. And that’s enough for me lol. It depends on your work load capacity. For me, the stem subjects are tricky to get your head around but geography is quite content heavy. So if you are happy to put a lot of work into deep understanding, go for it. It also really depends on what you want to do. If u want to drop one, unless you are taking a degree at uni that is maths, further maths is probably the one to drop. I’m taking maths at uni and the only thing having further maths does is drop the entry requirements. My other friends who take further but aren’t taking maths as a degree have no benefits other than a 4th alevel as their degrees aren’t maths. However, if you want to pursue maths, I recommend keeping further as it really strengthens your normal maths. Also, physics module3 overlaps with the mechanics section in maths so can really help in that respect. But again, it depends on what u want. If you really want to keep your options open, drop further as you can still take maths degrees without it and it has no major benefit in other degrees. But if u think u can take the work load, go for 5, you can always drop one for your second year.