Rounding to significant figures
Round a number to a stated number of significant figures.
- Start counting at the first non-zero digit.
- Use the following digit to decide whether to round up.
- Keep zeros that hold a whole-number place.
Example 1
Round to 2 significant figures.
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Example 2
Round to 2 significant figures.
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Remember
Keep zeros that hold a whole-number place.
Your turn
Round to 1 significant figure.
Check answer
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Round to 3 significant figures.
Check answer
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Round to 1 significant figure.
Check answer
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Round to 2 significant figures.
Check answer
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Round to 1 significant figure.
Check answer
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Round to 1 significant figure.
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Round to 3 significant figures.
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Round to 1 significant figure.
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Round to 2 significant figures.
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.
Round to 1 significant figure.
Blue: last place kept. Orange: deciding digit.
A deciding digit of 5 or more increases the blue digit by one. Replace discarded whole-number places with zeros.