show of hands

show of hands
a show of hands
a display of raised hands [in a group of people] that can be counted for the purpose of votes or surveys. •

We were asked to vote for the candidates for captain by a show of hands.

Jack wanted us to vote on paper, not by a show of hands, so that we could have a secret ballot.

* * *
{n. phr.} An open vote during a meeting when those who vote "yes" and those who vote "no" hold up their hands to be counted. * /The chairman said, "I'd like to see a show of hands if we're ready for the vote."/

Dictionary of American idioms. 2013.