The Banker Game is a Montessori collaborative math exercise that invites children to work together. This is perfect because elementary learners love to work with peers, especially when the work requires a large amount of cards to select from. The Banker Game’s main purpose is to multiply large multiplicands with one, two, three, or more digit multipliers in an abstract fashion. The Banker game likely follows the use of the Large Bead Frame and precedes the Checkerboard. It can be used by a single learner to solve equations or as a group of three or four learners where each learner assumes a role (customer, banker, cashier, bookkeeper).
Materials
Our set complete set, The Banker Game Complete Set, aims to provide all the materials necessary to experience the full benefits of such exercise. Our set consists of:
- Banker Game – a compartmentalized wooden box that contains numbered plastic cards
- Banker Game Task Cards – Set 1 (44 cards)
- Banker Game Task Cards – Set 2 (49 cards)
How to Use the Materials
For this exercise, you may use a large mat or 2 medium mats on the floor. Invite children to select the Banker Game from the shelf in the Math area. If you are working with one learner, you may use the Task cards to practice long multiplication independently. If you are working with a group of 2-3 learners (preferably 3), you may assign them roles based on their personal abilities. The most commonly used roles are customer, banker, and cashier. The customer’s job is to build and compute the multiplicand and multiplier together. The banker’s job is to fetch the partial products, and the cashier’s job is to compute the final product. Below is an example of how the Banker Game is used in conjunction with our Banker Game Task Cards with a 4-digit multiplicand, and a 1-digit multiplier. The control for errors is on the back of each card to promote continuous scaffolded independent work.
Set up the materials with the colored-background multiplicand cards to the left, from top to bottom (starting with 1), from right to left (ending with 9,000). Set up the grey multiplier cards in the middle, and the colored-numerals product cards to the right, from top to bottom (starting with 1 at the top), from right to left (ending with 9,000,000).
Working with a problem requires expanding its notation to facilitate the computation of a large number. In our example below, we have 4,267 taken 2 times. The Customer fetches the appropriate cards to build the multiplicand (4267) and the multiplier (2) and expands the number by separating the cards with the units at the top and the highest categories below one another. Now it is easier for a young learner to digest such a task. The customer says aloud that 7 taken 2 times equals 14 (if the child needs help with math facts, simply provide a multiplication control chart). Next, the banker fetches the partial product 14, which requires cards 4 and 10 from the product section.
The banker places the cards in a hierarchical fashion going from right to left, with the units to the right, followed by the tens, hundreds, thousands, etc. This way, the child sees that multiplication can be solved by simplifying the multiplicand and working with chunks of information. In a traditional computation of the equation 4,267 x 2, children miss the opportunity to truly understand how multiplication works. They might simply be following a procedure without necessarily developing mathematical skills that will be applicable in other contexts.
Finally, once all the partial products have been solved and laid out, the cashier is in charge of simplifying by adding all the units together and doing the same for the tens, hundreds, thousands, and so on. Once all the cards from all categories have been added, the cashier can discover the final product by overlapping the remaining cards with the unit card at the very top, right side. and the highest number at the very bottom of the pile of overlapping cards.
the Control for Errors on the Back of the Task Card
