Simple calculator, which can perform basic mathematical operations to implement using menu driven using Linux shell script in Ubuntu

echo Enter Two numbers:
read n1 n2
echo Enter your choice:
echo 1.Addition
echo 2.Subtraction
echo 3.Multiplication
echo 4.Divishion
read ch
case $ch in
1) add=`expr $n1 + $n2`
echo addition is: $add;;
2) sub=`expr $n1 - $n2`
echo subtraction is: $sub;;
3) mult=`expr $n1 \* $n2`
echo multiplication is: $mult;;
4) div=`expr $n1 / $n2`
echo division is: $div;;
esac