It isn't only numeracy that first-year undergraduates lack.
Literacy is also a serious problem, and so is ever-declining subject knowledge (history is a case in point).
Clearly, these deficiencies are the result of schoolteachers teaching ineffectively. But the methods they employ and the educational theories they put into practice, are learnt at university schools of education. University educationists help design the syllabuses for public exams and influence Ofsted, whose inspectors help to enforce their approved methods and theories in schools. It is educationists, then, who are ultimately to blame for deficiences.
Are formal teaching qualifications for academics, provided by those very educationists who have done so much to reduce the effectiveness of education in schools, really such a good idea? Perhaps the money that is spent on such courses might be better used for literacy and numeracy provision for undergraduates.