Optimizing Code

Hi I have some code for my game that checks what level you are on and if you are a certain level it enables the interactable component for the buttons one by one each level. I am new to programming so i was wondering if someone could help me optimize my code as i have to individually check each level in the update function at the moment Here is my code

 public class LevelManager : MonoBehaviour {
     public Click click;
     public GameObject levelholder;
     public float bargain;
     public float researchpoints;
     public float researchskill;
     public float researchlevel;
     public UpgradeManager ugpr;
     public AudioSource audio1963;
     public Button research;
     public UnityEngine.UI.Text Rlevel;
     public float rcost;
     public float baseCost;
     public UnityEngine.UI.Text Rcost;
 
 public void Update()
     {
         Rlevel.text = "Research Level: " + researchlevel;
         Rcost.text = "Cost to research: " + rcost;
         PlayerPrefs.SetFloat("ResearchL", researchlevel);
         PlayerPrefs.SetFloat("Rcost2", rcost);
         if (researchlevel < 3f)
         {
             ugpr.item3.interactable = false;
             ugpr.item4.interactable = false;
             ugpr.item5.interactable = false;
             ugpr.item6.interactable = false;
             ugpr.item7.interactable = false;
             ugpr.item8.interactable = false;
             ugpr.item9.interactable = false;
             ugpr.item10.interactable = false;
 
         }
          if(researchlevel == 4f)
         {
             ugpr.item3.interactable = true;
             ugpr.item4.interactable = false;
             ugpr.item5.interactable = false;
             ugpr.item6.interactable = false;
             ugpr.item7.interactable = false;
             ugpr.item8.interactable = false;
             ugpr.item9.interactable = false;
             ugpr.item10.interactable = false;
 
         }
         if (researchlevel == 5f)
         {
             ugpr.item3.interactable = true;
             ugpr.item4.interactable = true;
             ugpr.item5.interactable = false;
             ugpr.item6.interactable = false;
             ugpr.item7.interactable = false;
             ugpr.item8.interactable = false;
             ugpr.item9.interactable = false;
             ugpr.item10.interactable = false;
 
         }
         if (researchlevel == 6f)
         {
             ugpr.item3.interactable = true;
             ugpr.item4.interactable = true;
             ugpr.item5.interactable = true;
             ugpr.item6.interactable = false;
             ugpr.item7.interactable = false;
             ugpr.item8.interactable = false;
             ugpr.item9.interactable = false;
             ugpr.item10.interactable = false;
 
         }
         if (researchlevel == 7f)
         {
             ugpr.item3.interactable = true;
             ugpr.item4.interactable = true;
             ugpr.item5.interactable = true;
             ugpr.item6.interactable = true;
             ugpr.item7.interactable = false;
             ugpr.item8.interactable = false;
             ugpr.item9.interactable = false;
             ugpr.item10.interactable = false;
 
         }
         if (researchlevel == 8f)
         {
             ugpr.item3.interactable = true;
             ugpr.item4.interactable = true;
             ugpr.item5.interactable = true;
             ugpr.item6.interactable = true;
             ugpr.item7.interactable = true;
             ugpr.item8.interactable = false;
             ugpr.item9.interactable = false;
             ugpr.item10.interactable = false;
 
         }
         if (researchlevel == 9f)
         {
             ugpr.item3.interactable = true;
             ugpr.item4.interactable = true;
             ugpr.item5.interactable = true;
             ugpr.item6.interactable = true;
             ugpr.item7.interactable = true;
             ugpr.item8.interactable = true;
             ugpr.item9.interactable = false;
             ugpr.item10.interactable = false;
 
             if (researchlevel == 10f)
             {
                 ugpr.item3.interactable = true;
                 ugpr.item4.interactable = true;
                 ugpr.item5.interactable = true;
                 ugpr.item6.interactable = true;
                 ugpr.item7.interactable = true;
                 ugpr.item8.interactable = true;
                 ugpr.item9.interactable = true;
                 ugpr.item10.interactable = false;
 
                 if (researchlevel > 10f)
                 {
                     ugpr.item3.interactable = true;
                     ugpr.item4.interactable = true;
                     ugpr.item5.interactable = true;
                     ugpr.item6.interactable = true;
                     ugpr.item7.interactable = true;
                     ugpr.item8.interactable = true;
                     ugpr.item9.interactable = true;
                     ugpr.item10.interactable = true;
 
                 }
 
             }
 
         }
 
 

So i was wondering is there a better way to disable all buttons except for 3 when on level 4 and all buttons except for 3 and 4 when on level 5 and so on without a huge block of long code