500. Bentching
Brachos 5:2
When three people eat bread together, they must recite zimmun (the call to gather) before bentching. If there are from three to ten dining together, one says, “Let us bless the One of Whose bounty we have partaken.” The others respond, “Blessed be the One of Whose bounty we have partaken and by Whose goodness we live.” The leader repeats the latter phrase.
Brachos 5:3
Next, the leader recites the four brachos of bentching with the other diners answering amen after each bracha.