unexpected symbols

So I followed a video tutorial here and wrote the first script that was shown in the video but I got a bunch of unexpected symbol errors. I got errors for using these symbols: '=' '+' 'if' '=='

 using UnityEngine;
 using System.Collections;
 
 public class CurrencyConverter : MonoBehaviour {
 
     private static CurrencyConverter instance;
     public static CurrencyConverter Instance{
         get
         {
             return instance;    
         }    
     }
     
     void Awake()
     {
         CreateInstance();
     }
     
     void CreateInstance() 
     {
         if(instance == null)
         {
             instance = this;
         }
     }
     
     public string GetCurrencyIntoString(float valueToConvert, bool currencyPerClick, bool currencyPerSec)
     {
         string converted;
         if(valueToConvert >= 1000000000000)
         {
             converted = (valueToConvert / 1000000000000f).ToString ("f3") + " T";
         } else if(valueToConvert >= 1000000000)
         {
             converted = (valueToConvert / 1000000000f).ToString ("f3") + " B";
         } else if(valueToConvert >= 1000000)
         {
             converted = (valueToConvert / 1000000f).ToString ("f3") + " M";
         } else if(valueToConvert >= 1000)
         {
             converted = (valueToConvert / 1000f).ToString ("f3") + " K";
         }else 
         {
             converted = "" + valueToConvert;
         }
     }
 
     if(currencyPerSec == true)
     {
         converted = converted + " CPS";
     }
     
     if(currencyPerClick == true) 
     {
         converted = converted + " CPC";
     }
 }