CHEM 1021 Lecture Notes - Lecture 5: Trailing Zero, Graduated Cylinder, Decimal Mark
Document Summary
We can have one certain digit in the measurement of all three lengths, and one estimated or uncertain digit in these measurements. All measurements shown (made with this particular ruler) have two sig. figs. Scale - graduated cylinder - clicker #1 - 32. 3 (3 sig. Rule 1: the digits 1-9 are always significant (non-zero digits) o o. Rule 2: leading zeros are not significant. Zeros at the beginning of the number in a measurement. 0. 0634 sec 3 sig figs ---> 6. 34 x 10^-2 sec. If the number has a decimal point then the trailing zeros are always sig. 1. 000 g 4 sig figs: g 3 sig figs o. Zeros that are railing but no decimal point. Rule 1: 1st digit less than 5, leave it alone. Rule 2: 1st digit greater than 5, round up o o. Rule 3: 1st digit equals to 5, round up o. Rule 4: always round off at the end of a series of calculations.
