CalculatorWithTests/Calculator.cs

using System;

namespace Calculator
{
    public class Calculator
    {
        public float Add(int a, int b) => a + b;

        public float Subtract(int a, int b) => a - b;

        public float Multiply(int a, int b) => a * b;

        public float Divide(int a, int b)
        {
            if (b == 0)
                throw new ArgumentException("Division by zero");
            return a / (float)b;
        }

        public float Power(int a, int b)
        {
            int c = 1;
            for (int i = 0; i < b; i++)
            {
                c *= a;
            }
            return c;
        }
    }
}