The partner keys them in using the numerical pad on the keyboard or the row of numbers at the top of the regular keyboard. Set a time limit based on the skills of your students. Have students change places and repeat the activity. When both members of each pair have had a turn, have them check each other's work for accuracy. The one with the fewest errors wins and moves on the to the next round.
Rounds continue until there is one champion for that day.
Of course, you can have consolation rounds to keep the eliminated students in practice. Extensions To make the game even harder, handicap a champion by requiring him or her to hear and remember numbers, while affording the challenger the opportunity to see them as in normal play. If you have a repeat winner, have a different student challenge the champion each day. After a while, put the names of undefeated champs on an All-Time Numero Uno list. Because this game stresses numbers rather than verbal skills, it's a great confidence builder in situations where some students in the class know English only as a second language.