If you struggle to get to grips with a subject, trying to teach it would be pretty ridiculous, right?
Well we would all think so, yet a fifth of trainee teachers cannot do sums or spell according to shocking recent research, and one had 37 resits before passing a basic maths test.
The latest figures from the Training and Development Agency for Schools reveal that in 2009/10, a fifth of trainees failed both the numeracy and literacy tests first time round.
Some 6,957 failed literacy and numeracy on the second attempt, while 1,508 failed either discipline on their fifth attempt. One clearly innumerate trainee was allowed 37 resits to get through the maths paper.
Critics have spoken out against those that take multiple resits by saying that they should not be teaching and will have a detrimental impact on their pupils.
From next year, Education Secretary Michael Gove is limiting the number of retakes to just two.
Trainees have to pass basic skills tests in literacy, numeracy and ICT (information and communication technology) before they qualify for the classroom. The pass mark is a modest 60% yet figures show standards have fallen during the last five years.
Last year the figure was 80% for both. Under Mr Gove's plans, struggling trainees will no longer be allowed in the classroom yet critics say his crackdown does not go far enough.
No grasp of basics
Passing the numeracy test has been a requirement of Qualified Teacher Status since 2000, while literacy and ICT tests were made compulsory the following year.
The online tests, which students sit in the final year of teacher training, originally gave just four or five attempts to pass but the rule was scrapped by Labour in 2001 to allow unlimited resits.
According to the Daily Mail, Professor Alan Smithers, director of the Centre for Education and Employment Research at Buckingham University, said: "It's shocking we have allowed people to become teachers who don't fully grasp our language or handle numbers and who we have let slip through the net on the 37th attempt.
"The nature of tests is that ... people will be able to fluke them, which means they pass but have no proper understanding of the subject – much like with driving tests. Three attempts will reduce this possibility, but it does not go far enough."