The county assessor shall have general supervision over and direction of the assessment of all personal property in his or her county. He or she shall advise and instruct all deputies and assistants as to their duties and shall require of them that the assessment of property be uniform throughout the county and that property be assessed as directed by law.

The county assessor may, in extending a value on any item of taxable tangible personal property, reject all values that fall below two dollars and fifty cents and extend all values of two dollars and fifty cents or more to the next higher five dollars or multiples thereof, making all valuations end in zero or five.