Rounding to Significant Figures Flashcards

All 5 cards in this deck

What is the first significant figure of a number?

The first non-zero digit, counting from the left.
e.g. in $0.0874$ it is the $8$

What are the steps to round a number to 1 significant figure?
e.g. round $0.0874$ to 1 sf

1. Find the first non-zero digit: the $8$
2. Look at the next digit: $7$, which is 5 or more, so round the $8$ up to $9$
3. Keep the place value with zeros: $0.09$

True or false? In $0.0874$, the zeros after the decimal point count as significant figures.

False. Leading zeros are only placeholders; the first significant figure is the $8$

When rounding a large whole number to significant figures, what must you do to the digits you no longer need?

Replace them with zeros to keep the place value.
e.g. $87\,569$ to 3 sf is $87\,600$

True or false? Rounding $4.096$ to 3 significant figures gives $4.09$

False. The next digit is $6$, so the $9$ rounds up, giving $4.10$