input: Write a python function to design a class with methods to compute the square and cube of a given number.
  assert MathOperations(3).square() == 9
  assert MathOperations(4).cube() == 64
  assert MathOperations(5).square() == 25
output: class MathOperations:
      def __init__(self, number):
          self.number = number
  
      def square(self):
          return self.number ** 2
  
      def cube(self):
          return self.number ** 3