Thread: Need Help with this Java Calculator

Hello, I'm a beginner at this. This is my assignment and I need to program a calculator. Here is what i have so far:

import java.util.Scanner;
public class IntCalc { 
     public static void main(String[] args) 
     { 
            Scanner keyboard = new Scanner (System.in);
            BigDecimal princ = 0;
double interest = 0;
char added = '\0';
char type = '\0';
int years = 0;
boolean clear = false;
boolean done = false;
menu(princ, interest, added, type);
while(!clear)
{
//checking for valid inputs
if((added != 'a' || added != 's' || added != 'q') && (type != 's' || type != 'c'))
{
System.out.println("There was an error in your input, please try again.");
menu(princ, interest, added, type);
}
else clear = true;
}
String header = "Period     Beginning Amount     Interest Earned     Ending Amount   ";
String out = "";
if(type == 's') out = calcSimple(princ, interest, added, years);
else out = calcComp(princ, interest, added, years);
System.out.println(header);
System.out.println(out);
}
 
public String calcSimple(BigDecimal princ, double interest, char added, int years)
{
String o;
BigDecimal amnt = princ;
BigDecimal intEarned = princ*interest;
int num = 0;
if(added == 's') num = years*2;
else if(added == 'q') num = years*4;
for(int x = 0; x < num; x++)
{
o += IntegertoString(x+1) + "    " + IntegertoString(amnt) + "    " + intEarned + "    " + amnt+intEarned + "\n";
amnt += intEarned;
}
return o;
}
public String calcComp(BigDecimal princ, double interest, char added, int years)
{
String o;
Decimal amnt = princ;
BigDecimal intEarned = princ*interest;
int num = 0;
if(added == 's') num = years*2;
else if(added == 'q') num = years*4;
for(int x = 0; x < num; x++)
{
o += IntegertoString(x+1) + "    " + IntegertoString(amnt) + "    " + princ*interest + "    " + amnt+intEarned + "\n";
amnt += intEarned;
intEarned = princ*interest;
}
return o;
}
public void menu(BigDecimal princ, double interest, char added, char type, int years)
{
System.out.println ("This program will calculate simple and compound interest.");
        System.out.println (" ");
        System.out.println ("What is the principle amount?");
		  princ=input.next();
        System.out.println ("What is the interest rate?");
        interest=input.next();
System.out.println ("Will the interst be added anualy, semi-anualy or quartely? (a, s, q)");
		  added=input.next();
System.out.println("Is the interst simple or compound? (s, c)");
		  type=input.next();
System.out.println("How many years would you like to calculate the interest for?");
  	 	  years=input.next();
}
}

This is the Error Message I'm getting when I try to compile:

 ----jGRASP exec: javac -g IntCalc.java
IntCalc.java:32: cannot find symbol
symbol  : class BigDecimal
location: class IntCalc
public String calcSimple(BigDecimal princ, double interest, char added, int years)
                         ^
IntCalc.java:47: cannot find symbol
symbol  : class BigDecimal
location: class IntCalc
public String calcComp(BigDecimal princ, double interest, char added, int years)
                       ^
IntCalc.java:63: cannot find symbol
symbol  : class BigDecimal
location: class IntCalc
public void menu(BigDecimal princ, double interest, char added, char type, int years)
                 ^
IntCalc.java:6: cannot find symbol
symbol  : class BigDecimal
location: class IntCalc
            BigDecimal princ = 0;
            ^
IntCalc.java:35: cannot find symbol
symbol  : class BigDecimal
location: class IntCalc
BigDecimal amnt = princ;
^
IntCalc.java:36: cannot find symbol
symbol  : class BigDecimal
location: class IntCalc
BigDecimal intEarned = princ*interest;
^
IntCalc.java:42: cannot find symbol
symbol  : method IntegertoString(int)
location: class IntCalc
o += IntegertoString(x+1) + "    " + IntegertoString(amnt) + "    " + intEarned + "    " + amnt+intEarned + "\n";
     ^
IntCalc.java:50: cannot find symbol
symbol  : class Decimal
location: class IntCalc
Decimal amnt = princ;
^
IntCalc.java:51: cannot find symbol
symbol  : class BigDecimal
location: class IntCalc
BigDecimal intEarned = princ*interest;
^
IntCalc.java:57: cannot find symbol
symbol  : method IntegertoString(int)
location: class IntCalc
o += IntegertoString(x+1) + "    " + IntegertoString(amnt) + "    " + princ*interest + "    " + amnt+intEarned + "\n";
     ^
IntCalc.java:68: cannot find symbol
symbol  : variable input
location: class IntCalc
		  princ=input.next();
                        ^
IntCalc.java:70: cannot find symbol
symbol  : variable input
location: class IntCalc
        interest=input.next();
                 ^
IntCalc.java:72: cannot find symbol
symbol  : variable input
location: class IntCalc
		  added=input.next();
                        ^
IntCalc.java:74: cannot find symbol
symbol  : variable input
location: class IntCalc
		  type=input.next();
                       ^
IntCalc.java:76: cannot find symbol
symbol  : variable input
location: class IntCalc
  	 	  years=input.next();
                        ^
15 errors
 
 ----jGRASP wedge: exit code for process is 1.
 ----jGRASP: operation complete.

PLEASE HELP ME. Thank you