calculator Class?

[QuestionPlease]

I need to create a calculator class for my basic calculator application that will implement the functions of the Calculator?
The design of the calculator class should be in this


This is what I have so far, am so confused?

public class Calculator
    {
        private decimal currentValue;



        public Calculator()
        {
        }

        public Calculator(decimal currentValue)
        {
            this.CurrentValue = currentValue;
        }
        public decimal CurrnetValue
        {
            get
            {
                return currentValue;
            }
            set
            {
                currentValue = value;
            }

        }

        public decimal Add(decimal operand1, decimal operand2)
        {
            return operand1 + operand2;
            }
        public decimal Subtract(decimal operand1, decimal operand2)
        {
            return operand1 - operand2;
        }
        public decimal Multiply(decimal operand1, decimal operand2)
        {
            return operand1 * operand2;
            }
        
        public decimal Divide(decimal operand1, decimal operand2)
        {
            return operand1 / operand2;
            }


    }
}