Do We Need Kavanah to Make a Minyan?

(4) There are those who permit one to say a spoken part [of the service] in which [God's] holiness [is proclaimed] with 9 and a minor that is older than 6 and knows to whom we pray joins [them]. And their words were not seen for the great decisors. And the rule is that a slave or a woman is not joined [to the 9]. Gloss: And even if he has a Chumash [printed Torah] in his hand we do not join him [to the 9], although there are those who follow this practice to be lenient at a time of need [The Rosh and Mordechai and Hagahot Maimoni Chapter 9 of the Laws of Prayer]

(6) If one of the 10 started to pray and [being in a section where he] could not answer with them or he is sleeping, even this one is included with them.

(11) Transgressors who transgressed the public decrees or transgressed a transgression: if they do not excommunicate him, then he is counted in the minyan of 10.

When the Shaliach Tzibor (prayer leader) repeats the tefillah (of the Amidah), the community must be quiet, and to focus (have kavanah) on the blessings from the Hazan - [the community] responds "amen". And if there is not 9 people with intention for his blessings, this is similar to a blessing in vain. Therefore, each person his will do for himself as if there are not nine others, and he will have intention for the blessings of the Hazan.

With regard to answering amen, the Sages taught: One should not respond with an abbreviated [ḥatufa] amen, in which the first syllable is not properly enunciated, and a truncated [ketufa] amen, in which the second syllable is not properly enunciated, and an orphaned [yetoma] amen, in which the respondent is unaware of the blessing to which he is responding. Similarly, one should not quickly and indifferently discharge a blessing from his mouth. Ben Azzai says: Anyone who recites an orphaned amen, his children will be orphaned; one who recites an abbreviated amen, his days will be abbreviated and incomplete; one who recites a truncated amen, his days will be truncated. One who extends his amen, they will extend his days and years for him. Nonetheless, one should not prolong it extensively.

It is taught in a baraita that Rabbi Yehuda says: One who did not see the great synagogue [deyofloston] of Alexandria of Egypt never saw the glory of Israel. They said that its structure was like a large basilica [basileki], with a colonnade within a colonnade. At times there were six hundred thousand men and another six hundred thousand men in it, twice the number of those who left Egypt. In it there were seventy-one golden chairs [katedraot], corresponding to the seventy-one members of the Great Sanhedrin, each of which consisted of no less than twenty-one thousand talents of gold. And there was a wooden platform at the center. The sexton of the synagogue would stand on it, with the scarves in his hand. And because the synagogue was so large and the people could not hear the communal prayer, when the prayer leader reached the conclusion of a blessing requiring the people to answer amen, the sexton waved the scarf and all the people would answer amen.