Not quite sure about this one

Ive been teaching myself to write java by coming up with random
program ideas and working through them. I wrote this code to convert
certain values for measurements, but I seem to have run into a snag. I
am getting odd values for int choice. When it is read here:

int choice= 0;

        try{
            choice = dataIn.read();

it seems to start with an initial value of 48, though I declare it
with a value of 0. I suspect the
" dataIn.read() " should be changed, but not sure what is wrong here.
The program also ends before reaching the for loop, and I dont know
about that either. Thanks in advance for any help you all may be able
to offer.

Here is the code:

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author Ian
 */
public class OutputVariable{

    public static void main(String[] args){

        BufferedReader dataIn = new BufferedReader(new
InputStreamReader( System.in) );

        System.out.println("Press 1 for Temperature conversion");
        System.out.println(" 2 for Weight conversion");
        System.out.println(" 3 for Liquid conversion");

        int choice= 0;

        try{
            choice = dataIn.read();

        }catch( IOException e ){
            System.out.println("Error!");

        }
        System.out.println(choice);

     for(;choice<=3;){

        if(choice==1){
            System.out.println("Enter the Temp in fahrenheit:");

            double fah=0.0;
            double cel= (fah-32)*(5/9);

            try{
            fah = dataIn.read();

            }catch( IOException e ){
            System.out.println("Error!");

            System.out.println("The Temp in celcius = " + cel);

            }
        }

        if(choice==2){
            System.out.println("Enter the Weight in pounds:");

            double lbs=0.0;
            double kilo= (lbs*2.2);

            try{
            lbs = dataIn.read();

            }catch( IOException e ){
            System.out.println("Error!");

            System.out.println("The weight in kilograms = " + kilo);

        }

        if(choice==3){
            System.out.println("Enter the volume in gallons:");

            double gallon=0.0;
            double liters= (3.8*gallon);

            try{
            gallon = dataIn.read();

            }catch( IOException e ){
            System.out.println("Error!");

            System.out.println("The volume in liters= " + liters);
            }

        }
    }

  }

 }
}