Find the zero mark on the ruler
Identify the inch marks, usually the longest lines with numbers
Read the number at the last inch mark before the object ends
Count the smaller lines between inch marks
Each smallest line usually equals 1/16 inch
Use the halfway line for 1/2 inch
Use the longer quarter lines for 1/4 inch and 3/4 inch
Use the medium lines for 1/8 inch and 3/8 inch
Combine the whole inch number with the fraction
Align the ruler straight with the object for an accurate reading