The CVSS v3.1 equations are defined below.
The Base Score is a function of the Impact and Exploitability sub score equations. Where the Base score is defined as,
4 Where “Round up” is defined as the smallest number, specified to one decimal place, that is equal to or higher than its input. For example, Round up (4.02) is 4.1; and Round up (4.00) is 4.0.