Source code: http://codepad.org/SIcID3Q3
int main()
{
MENU:
std::string Choose;
std::cout << "\nYour choose(1 -> 6): ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, Choose);
if (Choose != "1" && Choose != "2" && Choose != "3" && Choose != "4" && Choose != "5" && Choose != "6")
{
std::cout << "\nLua chon cua ban khong hop le\n";
Sleep(1500);
goto MENU;
}
if (Choose == "1")
{
std::cout << "\a";
goto STT1;
}
else if (Choose == "2")
{
std::cout << "\a";
goto STT2;
}
else if (Choose == "3")
{
std::cout << "\a";
goto STT3;
}
else if (Choose == "4")
{
std::cout << "\a";
goto STT4;
}
else if (Choose == "5")
{
std::cout << "\a";
goto STT5;
}
else if (Choose == "6")
exit(0);
STT1:
std::string s1, s2;
std::cout << "\nNhap so thu 1: ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, s1);
std::cout << "\nNhap so thu 2: ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, s2);
std::string s3 = s1 + s2;
std::cout << "\nKet qua tong = " << s3 << std::endl;
std::string Choose2;
std::cout << "\nBan muon:\n";
std::cout << "\n1. Return Menu.\n";
std::cout << "\n2. Continue.\n";
std::cout << "\n3. Exit Program.\n";
if (Choose2 == "1")
{
goto MENU;
}
else if (Choose2 == "2")
{
goto STT1;
}
else if (Choose2 == "3")
exit(0);
STT2:
std::string s4, s5;
std::cout << "\nNhap so thu 1: ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, s4);
std::cout << "\nNhap so thu 2: ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, s5);
std::string s6 = s4 + s5;
std::cout << "\nKet qua hieu = " << s6 << std::endl;
std::string Choose3;
std::cout << "\nBan muon:\n";
std::cout << "\n1. Return Menu.\n";
std::cout << "\n2. Continue.\n";
std::cout << "\n3. Exit Program.\n";
if (Choose3 == "1")
{
goto MENU;
}
else if (Choose3 == "2")
{
goto STT2;
}
else if (Choose3 == "3")
exit(0);
STT3:
std::string s7, s8;
std::cout << "\nNhap so thu 1: ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, s7);
std::cout << "\nNhap so thu 2: ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, s8);
std::string s9 = s7 + s8;
std::cout << "\nKet qua tich = " << s9 << std::endl;
std::string Choose4;
std::cout << "\nBan muon:\n";
std::cout << "\n1. Return Menu.\n";
std::cout << "\n2. Continue.\n";
std::cout << "\n3. Exit Program.\n";
if (Choose4 == "1")
{
goto MENU;
}
else if (Choose4 == "2")
{
goto STT3;
}
else if (Choose4 == "3")
exit(0);
STT4:
std::string s10, s11;
std::cout << "\nNhap so thu 1: ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, s10);
std::cout << "\nNhap so thu 2: ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, s11);
std::string s12 = s10 + s11;
std::cout << "\nKet qua thuong = " << s12 << std::endl;
std::string Choose5;
std::cout << "\nBan muon:\n";
std::cout << "\n1. Return Menu.\n";
std::cout << "\n2. Continue.\n";
std::cout << "\n3. Exit Program.\n";
if (Choose5 == "1")
{
goto MENU;
}
else if (Choose5 == "2")
{
goto STT4;
}
else if (Choose5 == "3")
exit(0);
STT5:
std::string s13;
std::cout << "\nNhap vao thua so: ";
while (getchar() != '\n' && getchar() != EOF) {}
getline(std::cin, s13);
std::string s14 = s13;
std::cout << "\nKet qua giai thua = " << s14 << std::endl;
std::string Choose6;
std::cout << "\nBan muon:\n";
std::cout << "\n1. Return Menu.\n";
std::cout << "\n2. Continue.\n";
std::cout << "\n3. Exit Program.\n";
if (Choose6 == "1")
{
goto MENU;
}
else if (Choose6 == "2")
{
goto STT5;
}
else if (Choose6 == "3")
exit(0);
system("pause");
return 0;
}
There are 40 errors :
Need helps from eveybody, thank you so much 
P/S: Lúc giúp nói Tiếng Việt chứ đừng nói tiếng Anh nha, mình không hiểu gì đâu =)) Còn ở trên mình dùng Tiếng Anh để thay đổi không khí xíu thôi 



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