operations in methods dont get saved to my variable : This is my first time using stackoverflow. IDK if i am doing it right. So anyways, i am trying to make calculator on Java. I am not sure how to explain my problem. operations in methods dont get saved. when i try to add number, it doesnt apply to last state of it. it applies to first number i gave. can you help me? 
```
import java.util.Scanner;

public class gelismishesap
{
    public static void toplam(int k)
    {Scanner a = new Scanner(System.in);
        System.out.print(k + " + ");
        for(int i = 0; i<1; i++)
        {
            int b = a.nextInt();
            k += b;
            System.out.println(k);
        }
    }
    public static void cikarma(int k) {
        Scanner a = new Scanner(System.in);
        System.out.print(k + " - ");
        for(int i = 0; i<1; i++)
        {
            int b = a.nextInt();
            k -= b;
            System.out.println(k);
        }
    }
    public static void carpma(int k) {
        Scanner a = new Scanner(System.in);
        System.out.print(k + " x ");
        for(int i = 0; i<1; i++)
        {
            int b = a.nextInt();
            k *= b;
            System.out.println(k);
        }
    }
    public static void bolme(int k) {
        Scanner a = new Scanner(System.in);
        System.out.print(k + " / ");
        for(int i = 0; i<1; i++)
        {
            int b = a.nextInt();
            k /= b;
            System.out.println(k);
        }
    }
    public static void main(String[] args) {
        Scanner a = new Scanner(System.in);
        System.out.print("Sayı girin: ");
        int anasayi = a.nextInt();
        System.out.println(anasayi);
        while(true)
        {
           String b = a.nextLine();
        if(b.equals("q")) { break; }
        if(b.equals("a")) { toplam(anasayi); }
        if(b.equals("b")) { cikarma(anasayi); }
        if(b.equals("c")) { carpma(anasayi); }
        if(b.equals("d")) { bolme(anasayi); }
        }
    }
}
```