private EquationParts GetEquationPartToBeCorrected()
{
if (Operand1.Contains('?'))
{
return(EquationParts.Operand1);
}
if (Operand2.Contains('?'))
{
return(EquationParts.Operand2);
}
if (Result.Contains('?'))
{
return(EquationParts.Result);
}
else
{
return(EquationParts.Invalid);
}
}