Entry tests for anyone wanting to become a teacher in England are going to get much tougher.
The government says the tests used at the moment are too easy and wants the best people to train to be teachers.
The new exams, designed by head teachers, will have to be taken before people even start their training.
They will have to do more difficult maths problems and won't even be allowed to use a calculator.
If they don't pass the first time they will only have two more chances to take it.
People hoping to become teachers will have to take the new, tougher test, from next September.
Sally Coates, who led the Teachers' Standard review, said: "This is really important, because we have to have high standards of numeracy and literacy in our teachers."