significant digits.
for short they are called "sig. figs."
Significant
estimated
Estimated
None of the digits need be estimated.
The last digit is always the estimated digit in a number
Significant
It is important to consider the precision of the measuring equipment.
estimated
Estimated
Measuring Digits are TWELVE (inches) in the British System and HUNDRED (centimetres) in the Metric System
The last digit is always the estimated digit in a number
None of the digits need be estimated.
1
Your measurement should include one estimated digit.
Any digital device - as opposed to an analogue device.
analog
Significant Figure.