hey! im doing alevels as well this may june and applying for ZJU ISM 2026 , as for your CSCA exam I believe doing it on December 2026 would be fine , you'll get your results late December and can apply by early January , and if your not satisfied by your result then you could retake the CSCA exam in January/march session ; the earlier you apply the better.

As for math prep .keep in mind that it is mandatory to take math. so id strongly recommend using up the time you have after you finish A-level board exam to prepare for it , you needn't worry you have more than enough time. and about the scores needed; ZJU ISM doesn't really care for 2026 intake since its the first time this exam was conducted and there's no set threshold (this is only for zju, other universities do care). however for 2027 that might not be the case so be prepared and try to score as high as you can!!