Grading tolerance and significant figures

The % grading tolerance affects how Mastering grades numeric answers. Some numeric answers are graded as correct not only when they match the official Mastering answer, but also if they fall within an acceptable range of this official correct answer. The grading tolerance determines the range of answers accepted as correct for the acceptable variation or rounding error.

An example of this type of question might be "How many days are in a year?" The official answer is 365.24 days, but because a calendar contains 365 days, Mastering also considers this as correct. More examples are provided in the section below.

• The typical grading tolerance for most numeric answers in Mastering assignment questions is between 2% and 3%. This means a student's answer can be plus or minus this percent of the correct answer. For example, if the grading tolerance is 2% and the correct answer is 100, then answers within the range of 98 and 102 are also graded as correct.
• When a student’s answer doesn't match the official correct answer, but the answer is accepted as correct because it is within the grading tolerance:
  The answer feedback displays the answer the student entered, with a message saying that the answer was either rounded differently or used a different number of significant figures than required.

  If this result is needed for any later calculation in this assignment item, the student should keep all the digits and round only as the final step before submitting the answer. The answer box may change the display of the student’s answer to the official correct answer in Mastering.

The number of significant figures (also known as significant digits) a student enters in their answer is NOT graded by the system. Significant figures refers to the properly-formatted answer to which the % grading tolerance is applied.

• Students should use at least three digits or significant figures in answers, unless otherwise specified or unless the exact answer can be expressed using fewer than three significant figures. If higher precision is required, or lower precision is allowed, this is specified in the question or its instructions.
• When students must do multiple calculations to get an answer:
  They should use more significant figures than required during each calculation and round at the end only. Rounding too early can cause the final answer to be outside of the allowed grading tolerance range, even if correctly calculated!

A question asks students to determine the area of a rectangle with sides of length L and width W. The area is the product of the length and the width (that is, area = L x W).

You can use the Simple Editor to tighten or loosen the grading tolerance in an assignment item that contains numeric answers. To do this, you copy and edit the item. Items that use the numeric or symbolic answer type contain the % grading tolerance setting. More about the grading tolerance setting (in Simple Editor Help)