The Dot Game: Static subtraction
How static subtraction is done with the Dot Game
The directress begins the activity by reading the operation through with the child that is written on the right-hand side of the dot board in expanded notation, for example: (8697 - 4352) The directress then tells the child that they will be making the numbers with dots on the paper.
She uses the green marker to draw seven dots in the unit collum. The child is then asked to draw nine dots in blue in the tens collum, six dots in red in the hundreds column, and eight dots in green in the thousand column.
The directress then reminds the child that they need to take two dots away from the seven dots in the unit column, she crosses out two dots from the right to the left, using the green marker. She then counts the remaining dots (5) and records the answer in green in the unit column.
The child is encouraged to continue in the same manner with the tens, hundreds, and thousands, ensuring to record the answer in the correct coloured marker, in the correct column. The directress reads through the operation and the answers with the child once it is complete.
What the child learns by doing this activity
This activity reinforces the (-) sign as well as place value in the decimal system and expanded notation. The child gets more practice with subtraction using less concrete materials.
Looking for more Montessori activities?
Here is a list of all the Montessori Maths activities including Early Maths, Introduction to the Decimal System, Seguin Boards, The Hundred Board, The Short Bead Stair, Bead Chains, The Snake Game, Group Operations, The Large Number Rods, Recording with the Small Number Rods, The Short Bead Stair, The Strip Boards, The Boards, The Stamp Game, The Abacus, The Dot Game, and Fractions. Just click on the page you want to learn about to go there.
Early Maths
Introduction to the Decimal System
The Short Bead Stair
Seguin Boards
The Hundred Board
Bead Chains
The Snake Game
Group Operations
Large Number Rods
Recording with the Small Number Rods
The Short Bead Stair
The Strip Boards
The Boards
The Stamp Game
The Abacus
Operations with the Abacus: Static addition (without change)
Operations with the Abacus: Static multiplication (without change)
Operations with the Abacus: Static subtraction (without change)