Which rounding rule applies when the first dropped digit is less than 5?

When rounding off, if the first dropped digit is greater than 5, the retained digit is:

Which statement correctly describes a non-physical quantity?

If repeated readings are close to each other but not near the true value, they are:

Why were standard units introduced?

Accuracy of a measurement means:

Which of the following is a complete measurement?

Precision of a measurement depends mainly on:

Which SI base unit and symbol are correctly matched?

How many significant figures are in 2.40 mm?

Which derived unit is equivalent to metre per second?