Precision

Precision is the number of significant figures or decimal places of variables shown after calculations. Precision affects the decimal numbers shown in wordings, feedback, and so. When rounding, the rule used for tie-breaking is half-up.

Consider the number 12.345

Precision

Rounded to significant figures

Rounded to decimal places

Precision is not the allowed deviation between students and correct answers; that is Tolerance. But precision can harm the comparison if set improperly. Precision affects the correct answer, how it's shown to the student, and also the actual value. The student answer will be compared with the correct answer that has been rounded using precision. If the precision number is smaller than the tolerance number, the correct answer will be rounded too much, probably outside the tolerance range. So remember to set the precision number always more significant than the tolerance number.