Identify the unit markings on the ruler
Find the zero mark
Place the ruler so the zero mark aligns with the starting point
Read the whole number at the end point
Count the smaller marks between whole numbers
Determine the fraction or decimal based on the smallest divisions
Add the whole number and the fractional part
Use the correct unit, such as inches or centimeters
Check that the ruler is aligned straight with the object
Read from the correct side of the ruler