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When my oldest grandson, Dusty, started kindergarten, I attended an orientation in an effort to familiarize myself with his school and become acquainted with school personnel. After introducing her faculty and staff, the principal announced that she and the classroom teachers encouraged parents and grandparents to get involved. As a college mathematics instructor, I have shared several ideas for classroom activities with my colleagues and students taking my Mathematics for Elementary Teachers course. Among them is a game that introduces base-ten grouping and trading.

This article describes the Dollar Game and what happened when I brought the game to my grandson's classroom.

The Game

The Dollar Game gives children an opportunity to make and trade groups of ten. To play the game, children need the following materials:

* an 8 1/2" x 11" game mat for each player, on which three columns are labeled Dollar, Dimes, and Pennies;

* one number cube per group or table of players

* enough pennies to allow several players simultaneously to reach a count of ten;

* one dollar per player; and

* one "banker" per group of players (groups of four players worked best for us).

Game mats can be made out of unlined paper and covered with clear contact paper for an inexpensive protective coating, and children can use real or play money for counting and exchanging. The "bankers" could be parents or grandparents of some of the players, college students completing a practicum, or high school or upper elementary students who have volunteered to be teachers' aides.

The Dollar Game works best with groups of three to five players, not including the banker. One player tosses the number cube, then counts out pennies according to the number on the number cube. The same player then places the pennies in the Pennies column of his or her game chart. Each player continues to take a turn. When a player obtains ten pennies, the banker exchanges the pennies for one dime. The player places the dime in the Dimes column of the game mat and leaves the remaining pennies in the Pennies column. This process continues until a player obtains ten dimes in the Dimes column. The player exchanges the ten dimes for a dollar and is proclaimed the winner of the game.

Our Experience

Our game mats were made out of colored construction paper and covered with clear contact paper. Each group had a mat of a different color and a pencil-box bank containing \$5 in pennies \$4 in dimes, and five, one-dollar bills. (1 used real money to stimulate interest in the game.) Four college students, who had completed Mathematics for Elementary Teachers I and II and a mathematics methods course, acted as the bankers and supervised the exchanges to keep a sharp eye on the money.

Sixteen students were in the kindergarten class that day, so each group consisted of four players. The classroom had no desks, only tables, so each group had its own table. I briefly explained the rules of the game and how to win. Then the bankers went to work. The classroom teacher and I moved from group to group, observing and helping.

After Dusty's second or third toss, he said, "Hey, Grandma, I have seven pennies. Now I only need three more and I can trade for a dime!" He had decomposed 10 into 7 and 3. I went over to his table so I could watch him take his next turn. I was curious to see whether he could make the trade correctly if he tossed a large enough number. On his next toss, he got a 4. He knew he had enough to trade because "four is more than three, and I only need three," but he carefully counted out ten pennies and gave them to his banker. He then took the dime, placed it in the Dimes column, and left the remaining penny in the Pennies column. I could not believe how much Dusty had learned. Two months earlier, when I first exposed him to the game, he could neither compose …