The free-response part of the SAT Math practice test allows learners to type in characters other than numbers, "-" and "/". This is very annoying because learners can for example put x = 3 even though the actual SAT doesn't allow that and then they get the question wrong even though the answer was 3. So the coding needs to be fixed so that only numbers, the divided by symbol, and the minus are allowed. Also restricting the box to the number of characters on the SAT would be cool too because that way learners can realize that their answer is wrong because it doesn't fit in the box (like they would when taking the test).