Write a program for calculator ? | Shell Program |

#!/bin/bash
echo "Enter two numbers:"
read a
read b
echo "Enter choice:"
echo "1.Addition"
echo "2.Substraction"
echo "3.Multiplication"
echo "4.Division"
echo "Enter a choice"
read ch
case $ch in
1)res=`echo $a+$b|bc`;;
2)res=`echo $a-$b|bc`;;
3)res=`echo $a*$b|bc`;;
4)res=`echo "scale=2;$a/$b"|bc`;;
esac
echo "Result=$res"


OUTPUT

50
20
Enter choice:
1.Addition
2.Substraction
3.Multiplication
4.Division
Enter a choice
2
Result=30