Tic-Tac-Toe
I received this idea from another teacher this summer. It's the most productive 10 minutes of the day.
During the day, the students fill out a tic-tac-toe grid on scrap paper, placing one vocabulary word that they choose from my words on index cards around the room. I keep the cards up one month, and at the beginning of the month, many of the words have not been taught, yet. I include 50% new words to encourage them to find the meanings on their own.
I wrote the words on column A of my spreadsheet. In cell D1, I put in a function to choose a random number between 1 and x, x being the number of words. My computer chooses a number that matches the number of a word in column A. I call out a definition for the word, and if a student has a match, s/he puts an X in that space on her/his paper.
I move that word to column B, so that I know I have already chosen that word. If the computer picks that word again, I choose the word below it. (Note, the computer is at my desk and the students cannot see the screen).
If a student gets Tic-Tac-Toe (3 in a row), as in Bingo, I check the words and their spellings. The winner gets a prize from the prize box.
If I need to skip a day for time, I play for 2 winners the next day by just continuing playing after one student has won. I've found it best to set a time limit, rather than waiting until having a winner.
On the computer, I've found it best to sometimes save the screen at the end of the game, and secretly not use the same words the next day. It gives a more random choosing of the words. I started out small, but now I'm up to 107 words this month.
The students are demonstrating knowledge of the words, even the ones they don't choose, several are looking new words up in the dictionary or texts at the beginning of the month before the words are formally introduced, and the students love this game! They are very disappointed when we don't play.
I found it best to congratulate the winner as a class, and to say "good try" to students who think they've won and allow the class to encourage that student, also, as s/he goes back to try again.