Any absences that are foreseeable must be discussed with the instructor before lab meeting time. Arrangements may possibly be made with the lab assistant to make-up a lab. Every measurement you will make requires two parts. Record data and express results in scientific notation when dealing with very small or very large numbers. Most of the numbers involved in experimental work are arrived at through some process of measurement.
Any experimental measurement is approximate or uncertain by some amount.
The significant digits of an experimental measurement indicate its degree of certainty. Your proper use of significant digits, then, will prevent your claiming a greater accuracy than your measurements allow. In the 6.74 cm measurement, the 6 and the 7 were read directly and are, therefore, known with certainty. The ambiguity is resolved by the experimenters' knowledge of the measuring instrument telling him how many significant digits are justified. Multiplication or division of two or more numerical measurements.