rules of sig figs

Rule #1

All non zero digits are significant

Ex. for rule #1

1.23cm (3sf)

Rule #2

A zero between 2 non zeros IS significant

Ex. for rule #2

102cm (3sf)

Rule #3

A leading zero is NOT significant

Example for rule #3

0.000001cm (1sf)

Rule #4

A trailing zero IS significant IF a decimal point is present

Example for rule #4

120 (2sf); 120.(3sf)

Multiplication/division rule

The # of sign figs in the answer should be the same as the measurement with the least # of sign figs

Multiplication/division rule example

3(1sf)X2.5(2sf)=8(1sf)

Addition/subtraction rule

The number of decimal place in the answer should be the same as the measurement with the least amount of decimal places

Addition/subtraction rule example

4.50(hundredths)+9.775(thousandths)=14.375—>14.38

Defined/counted rules

These numbers have an infinite # of sign figs. They are EXACT

Defined/counted number example

1,000mL=1L is infinite because it is an exact measurement