How do I use math on variables?

How do I do math? Like, multiply float variables by decimals so I don’t need 3 different movement variables. i.e. 1 is the set as walk speed, x1.5 for run speed, x0.6 for strafe speed.

Here is USharp example.

using UdonSharp;
using UnityEngine;
using VRC.SDKBase;
using VRC.Udon;

public class SpeedAdjustment : UdonSharpBehaviour{

    public float BaseWalkSpeed = 1;

    void Start(){
        VRCPlayerApi Player = Networking.LocalPlayer;

        float RunSpeed = BaseWalkSpeed * 1.5f;
        float StrafeSpeed = BaseWalkSpeed * .6f;

        Player.SetWalkSpeed(BaseWalkSpeed);
        Player.SetRunSpeed(RunSpeed);
        Player.SetStrafeSpeed(StrafeSpeed);
    }
}