practise and practise only last you for a short while. Maybe can
get distinction for O level, but after that also forget liao.
To make it last, you need to understand the fundamental. Then, 20
years later still can do those sums without problem. Of course, if
you intent to drop any maths alltogether after O level, then just
practise. But note that you cannot escape maths unless you drop all
the science subject as well. Things like physics, computer,
econmics and statistics has tons of maths in there, if not more
sometimes.