Our head of sixth brought up resitting students yesterday, and how low the pass rate for maths is, really. We do allow students to resit English or maths alongside their Level 3 studies, and we also have a small number of students who join us without GCSEs (usually from outside the UK) who do both (one in Y12, and one in Y13).
Our pass rate for maths post 16 is a bit better than the national average BUT we only offer Level 3 courses, so it's not really a fair comparison. I think part of the issue is motivation (obviously), and being in a class of students who really don't want to be there isn't the best learning environment!
One thing we're trying this year, is the option for students who got a 4/5 but want to resit for a 5/6 to join our English and maths resit classes. One, this hopefully gives them more options when they leave us, but two, it will hopefully increase the overall motivation of the resit classes, and make them a better learning environment.
What I'd really love data on is student progress over time post 16- if students who get 3s are eventually working their way up to 4s, but students who get 1s and 2s aren't (for example), then perhaps we need to look at other options for those students?
I've taught (in science) students who struggle with really basic arithmetic, even at 15/16- they rely on a calculator to do 2 digit addition or subtraction- if they have to use a decimal or a negative number, then they have no idea if the answer on their calculator is sensible. Some of them struggle to read off a scale (e.g. temperature, from an analogue display) or tell the time from a clock. I'm not sure two years of additional teaching is enough for these students.
Equally, I've taught students who are borderline 3/4 across maths and science, and with enough chances, and small group teaching, they probably will get their 4, which is great!