Answer Flags: Fractions, Decimal Accuracy, Accuracy According to the System of Significant Figures

What are answer flags?

Certain flags can change what is accepted. These are placed at the beginning of the answer. For example, ###+-### allows both positive and negative answers.

Fractions

• ###allfrac### allows fractions that are not in their simplest form. With this flag, the extra answer 22/46 is now allowed, but also 44/92 and so on.
• ###nofrac### disallows all fractions as answers. In this case, 0.47826086956 , 0.478261, 0.4782609, 0.47826087, 0.478260870, 0.4782608696 would be accepted.
• ###yesfrac### allows fractions in answers. This is useful because the below functions related to decimal accuracy by default disallow fraction input.
• ###onlyfrac### doesn’t allow decimal format answers

Decimal accuracy

• ###1dp### exactly accurate to one decimal place is accepted. Only 0.5 is accepted
• ###+1dp### accurate to one or more decimal place is accepted. 0.5 … 0.47826086956 are all acceptable.
• ###1:3dp### accurate to 1 to 3 decimal places is accepted. 0.5, 0.49, 0.478 are accepted

Accuracy according to the system of “significant figures”

• ###1sf### exactly accurate to one significant figure is accepted. 

Definition of a significant figure: We start from the left, and start at the first non-zero number. This is our first “significant” place. We then move left to right to cover the number of significant places demanded (zeros are now included). The number is then rounded using only these digits and zeros in other places as needed to keep the magnitude the same.

Example: 12.345 and 0.012345: