Setting Text.text with Slider number in New UI

I have this code so far but I'm not sure what I'm doing wrong.

 using UnityEngine;
 using System.Collections;
 using UnityEngine.UI;
 
 public class SliderUITextUpdate : MonoBehaviour {
     string sliderTextString;
     Text sliderText;
 
 
     void start(){
         sliderText = GetComponent<Text> ();
         }
 
     public void textUpdate (float textUpdateNumber){
         textUpdateNumber.ToString (sliderTextString);
         sliderText.text = sliderTextString;
     }
     // Update is called once per frame
     void Update () {
     
     }
 }