Sunday 24 May 2015

Montessori Activity: Subtraction Snake Game

AGE: 5.5 to 6 years (After the child has tried the Addition Snake Game)

OBJECTIVE(S):

1. To illustrate subtraction.

MATERIALS:

1. 1 box containing 5 sets of colored short bead bars (1-9).
2. 1 box containing 25 golden 10-bars.
3. 1 box containing 1 set of black and white bead stair.
4. 1 box containing grey bead bars (subtraction bars)
5. 1 notched cardboard or plastic counter to act as marker.
6. 2 empty containers, one to contain the addition bars, and the other to contain the subtraction bars that have been counted.
7. 1 mat or felt cloth to work on.

PRESENTATION:

1. Place the black and white bead stair at the upper right hand corner of the mat and arrange them into a triangle with the 1 black bead at the bottom and the 9 bead at the top.

2. Introduce the subtraction beads and tell the child that they are grey and dark grey.

3. Place the notched card below the stair and explain, "This card is to mark where we finished counting."

4. Start by making a random snake alternating between the following colored bead bars and the subtraction beads that will give the end result as zero as follows:

9
7 ------------------------ 4
2 ------------------------ 5
5 ------------------------ 9
8 ------------------------ 7
6 ------------------------ 8
4 ------------------------ 6
9 ------------------------ 9
3
1 ------------------------ 6

5. Count the colored bead bars and insert the marker after the 10th bead has been counted, i.e. blue 9-bar and first bead of green 2-bar.

6. Place a golden 10-bar next to the colored bead bars.

7. Count the remaining beads of the bead bar, in this case 1 bead, and place the appropriate black and white bead bar to next to it, i.e. black 1-bar. In total, you now have 11 beads.

8. Remove the colored bead bars already counted into an empty container.

9. Continue in the same manner until you reach a grey subtraction bead bar. Count the number of beads in the grey bar, i.e. grey 4-bar, and say, "That means we need to take away 4 beads."

10. Take 4 away by counting the 4 beads backwards and mark it with the marker.

11. Count the remaining from the golden 10-bar. In this case, you have 7 beads remaining. Place a black and white 7-bar next to the golden 10-bar.

12. Remove the golden 10-bar, the black 1-bar and the grey 4-bar and put them aside or into an empty container. Join the snake.

13. Continue in the same manner by counting the beads and insert marker when you reach the 10th bead, i.e. black and white 7-bar and first 3 beads from the brown 8-bar.

14. Place a golden 10-bar next to the beads you just counted to 10.

15. Count the remaining beads of the bead bar, in this case 5 bead, and place the appropriate black and white bead bar to next to it, i.e. black 5-bar. In total, you now have 15 beads.

16. Remove the black & white 7-bar and the brown 8-bar to their respective places. Join the snake.

17. Count the number of beads in the grey bar, i.e. grey 7-bar and and say, "That means we need to take away 7 beads."

18. Take 7 away by counting the 7 beads backwards and mark it with the marker.

19. Count the remaining from the golden 10-bar. In this case, you have 8 beads remaining. Place a black and white 8-bar next to the golden 10-bar.

20. Remove the golden 10-bar, the black 5-bar and the grey 7-bar to their respective places. Join the snake.

21. Continue in this manner until all beads have been removed and the snake eliminated.

VIDEO DEMONSTRATION:

Note: The video presentation is in Spanish, but it is very intuitive.

CONTROL OF ERROR:

1. Arrange all the grey bars vertically from longest to shortest.
2. Place the colored bead bars in the same manner below the grey bars.
3. Pair the grey bead bars and colored bead bars together according to length and say, i.e. 6 take away 6 is zero.
4. Exchange if required to have the same amount of colored bead bars as grey bead bars until there are no more matching required.
5. Then match the golden 10-bars with the rest of the colored bead bars - they should match perfectly.

Or

1. Arrange the colored bead stair in a line.
2. Arrange the grey bead bars next to it in a line - they should match perfectly.

Just preparing this as something new to present to J, as he is complaining that I keep doing the same thing. The pictures will come later.

REFERENCES:

The Montessori Subtraction Snake Game is available from Amazon:

1. Place the black and white bead stair at the upper right hand corner of the mat and arrange them into a triangle with the 1 black bead at the bottom and the 9 bead at the top.

2. Introduce the subtraction beads and tell the child that they are grey and dark grey.

3. Place the notched card below the stair and explain, "This card is to mark where we finished counting."

4. Start by making a random snake alternating between the following colored bead bars and the subtraction beads that will give the end result as zero as follows:

5. Count the colored bead bars and insert the marker after the 10th bead has been counted, i.e. blue 9-bar and first bead of green 2-bar.

6. Place a golden 10-bar next to the colored bead bars.

7. Count the remaining beads of the bead bar, in this case 1 bead, and place the appropriate black and white bead bar to next to it, i.e. black 1-bar. In total, you now have 11 beads.

8. Remove the colored bead bars already counted and put them aside or into an empty container.

9. Continue in the same manner until you reach a grey subtraction bead bar. Count the number of beads in the grey bar, i.e. grey 4-bar, and say, "That means we need to take away 4 beads."

10. Take 4 away by counting the 4 beads backwards and mark it with the marker.

11. Count the remaining from the golden 10-bar. In this case, you have 7 beads remaining. Place a black and white 7-bar next to the golden 10-bar.

12. Remove the golden 10-bar, the black 1-bar and the grey 4-bar and put them aside or into an empty container. Join the snake.

13. Continue in the same manner by counting the beads and insert the marker when you reach the 10th bead, i.e. black and white 7-bar and first 3 beads from the brown 8-bar.

14. Place a golden 10-bar next to the beads you just counted to 10.

15. Count the remaining beads of the bead bar, in this case 5 bead, and place the appropriate black and white bead bar to next to it, i.e. black 5-bar. In total, you now have 15 beads.

16. Remove the black & white 7-bar and the brown 8-bar to their respective places. Join the snake.

17. Count the number of beads in the grey subtraction bar, i.e. grey 7-bar and say, "That means we need to take away 7 beads."

18. Take 7 away by counting the 7 beads backwards and mark it with the marker.

19. Count the remaining from the golden 10-bar. In this case, you have 8 beads remaining. Place a black and white 8-bar next to the golden 10-bar.

20. Remove the golden 10-bar, the black 5-bar and the grey 7-bar to their respective places. Join the snake.

21. Continue in this manner until all beads have been removed and the snake eliminated.

1. Arrange the colored bead stair in a line.

2. Arrange the grey bead bars next to it in a line - they should match perfectly.