If you keep making “careless” mistakes, stop treating them as random. Repeated errors usually have a pattern: signs are dropped, units are missed, instructions are skimmed, numbers are copied wrongly, working becomes compressed, answers are not checked, or speed rises before accuracy is stable.
Collect several mistakes and classify them. Then design one small control for the dominant pattern—for example, underline command words, write units before the final line, leave one line per algebraic step, or reserve the last minutes for a specific checking sequence. A vague instruction to “be more careful” is weak; a visible procedure is much easier to train.
Use the Examinations & Assessment Hub for exam execution, and the Diagnostics & Recovery Hub if the mistakes reveal an underlying knowledge or processing weakness.