Near the end of his Sharh Ma‘ani al-Athar(2:371, Maktabah Haqqaniyyah), Imam al-Tahawi (d. 321 H) narrates:

‘Ali ibn ‘Abd al-Rahman and Yahya ibn ‘Uthman narrated to us, they said: ‘Abd Allah ibn Yusuf narrated to us: From Yahya ibn Hamzah, he said: Wadin ibn ‘Ata’ narrated to me that al-Qasim Abu ‘Abd al-Rahman narrated to him, he said: One of the companions of the Messenger of Allah (Allah bless him and grant him peace) narrated to me, he said:
“The Prophet (Allah bless him and grant him peace) prayed with us on the day of ‘Id, so did takbir, four [in the first rak‘ah] and four [in the second], and then he turned to us with his face when he finished and he said: ‘Do not forget, [the takbirs of ‘Id are] like the takbir of janazah.’ And he gestured with his fingers and clutched his thumb (signalling the number four).”

Meaning

The “four” takbirs of the first rak‘ah mentioned in this narration includes the opening takbir (takbirat al-iftitah) as the Prophet (peace and blessings be upon him) drew a comparison with the takbirs of Janazah in which one of the four takbirs is also of the opening takbir. Furthermore, the four takbirs in the second rak‘ah includes the takbir said when going into ruku‘. Hence, the additional takbirs are in fact six.

This meaning is clear from other narrations, some of which are reproduced below..........
www.darultahqiq.com/proofs-for-the-hanafi-procedure-of-sa...