My teacher never says if we can or cant use calculators until the last couple days leading to test and if you ask she gets mad and wont tell me. if calculators are allowed can your school change the rules and say you can not use calculators or does every test in every school have to apply by that rule
For externals (apart from MCAT), you are allowed to use calculators. Your teacher however might have a reason for not wanting you to use one for a particular practice test. Generally you are allowed to use them for internals so leading up to an internal it would pay you to check with your teacher so you know either way. MT4
See for internals:
Students are expected to have access to appropriate technology that will enable students to develop and show their own thinking in solving problems. For statistics standards this would include statistical software.
For externals, except the MCAT: