Unit conversion is a multi-step process that involves multiplication or division by a numerical factor, selection of the correct number of significant digits, and rounding. This multi-step process is presented in NIST SP 1038 - 2006 (Section 4.4), including a rounding procedure for technical documents, specifications, and other applications such packaged goods in the commercial marketplace and temperature. Common conversion factors are also listed (Section 5).
Convert 5 m to ? cm