Montessori Activity: Subtraction Board (减法[jiǎn fǎ])

 

AGE: From 4.5 years old

OBJECTIVE(S):

To teach counting and subtraction of the unit place value in a concrete manner seeing the minuend and then taking away the subtrahend:

- Minuend (被减数 [bèi jiǎn shù]): the first number in a subtraction (a quantity or number from which another is to be subtracted).
- Subtrahend (减数 [jiǎn shù]): the second number in a subtraction (the number to be subtracted)
- Difference (剩[Shèng])

MATERIALS:

1. Homemade Addition Board using drawing block and green ribbon, green being the Montessori color for subtraction and making sure that your child associates the color of green with subtraction
2. 1 cup with glass pebbles
3. 1 set of number cards or number tiles (optional)
4. 1 set of equation cards (optional, you can also write the equation on a piece of paper)
5. 1 subtraction worksheet/paper, 1 pencil and eraser
6. 1 mat

PRESENTATION:

1. Lay out the materials on the table.

2. Explain that addition means putting things together and subtraction means taking them apart.

3. Read the problem to your child, e.g. 7-5=?

4. Have your child place 7 pebbles onto the minuend section on the subtraction board counting them as you go along. Then point to the number 7 in the problem and say, "You have 7 pebbles." Place the number tile 7 below the pebbles.

6. Transfer 5 pebbles from the minuend to the subtrahend section counting them as you go along, point to the number 5 in the problem and say, "You took away 5 of them. Place the number tile 5 below the pebbles.

8. Ask, "How many pebbles do you have left?"

9. Transfer the 2 pebbles from the minuend to the difference section, counting them as you go along and say, "You have 2 pebbles left. We say 7 take away 5 equal 2." Place number tile 2 below the pebbles.

10. Ask your child to repeat the problem and answer, saying "7-5=2" and write the answer on the worksheet.

11. Repeat this process with other subtraction problems.

VIDEO DEMONSTRATION:

https://www.youtube.com/watch?v=Xrg8tC9A_Ho

ADDITIONAL INFORMATION:

J tried this on 17 May 2014 (5y2m12d) for the first time. He was able to do them. We continued with this activity every day. However, J prefers the Singapore Maths Assessment book though to this Montessori subtraction board... children can be very different. It doesn't matter which method as long as they are learning. J had fun coloring the answer from the Singapore Maths Assessment book (so black and white pages can be a blessing after all.)

REFERENCES:

18 May 2014 (5y2m12d)

 

19 May 2014 (5y2m14d)

Montessori Activity: Addition Board (加法 [jiāfǎ])

 

I learned how to make the Addition Board from Montessori Live Educator Training Program.

AGE: 4.5 to 6 years (after the child has worked with numerals and counters)

OBJECTIVE(S):

1. To teach counting and addition of the unit place value in a concrete manner.
2. To teach the definition of addend (加数 [jiā shù]): a number to be added to another (Addend + Addend = Sum) (加数加加数等于总和)

MATERIALS:

1. Homemade Addition Board using drawing block and red ribbon, red being the Montessori color for addition and making sure that your child associates the color of red with addition
2. 1 cup with glass pebbles
3. 1 set of number cards or number tiles (optional)
4. 1 set of equation cards (optional, you can also write the equation on a piece of paper)
5. 1 addition worksheet/paper, 1 pencil and eraser
6. 1 mat

PRESENTATION:

1. Lay out the materials on the table.

2. Have your child read the first equation card: “3+4=?”

3. Have your child pick the first addend 3 glass pebbles, count them and place them on the first addend position on the addition board.

4. Have your child pick the second addend pink 4 glass pebbles, count them and place them on the second addend position on the additiona board.

5. Have your child label the addends with the number cards 3 and 4 respectively.

6. Have your child move the glass pebbles to the sum position on the addition board and say, "Addend plus addend equal sum."

7. Have the child count the total number of beads: “1,2,3…7” and label it with the number 7 card.

8. Ask the child write or paste the result onto the equation and say: “3+4=7”.

9. Return the pebbles and encourage your child to try the different combinations from the worksheet.

VIDEO DEMONSTRATION:

http://youtu.be/skzjbD1mw8o
http://youtu.be/LVj1ynsJnKA

CONTROL OF ERROR:

1. Verification by the teacher.
2. Addition Control Chart.

VARIATIONS:

Other materials may be substituted for the glass pebbles such as milk carton caps, shells, buttons and so on.

For addition of ten place value, you can also use the golden beads and colored bead stairs:

29 August 2014 (5Y5M24D) - Addition of ten place value

REFERENCES:

https://www.youtube.com/channel/UCYsNVhM9ANGcQF_wfysxeHw

ADDITIONAL INFORMATION:

J (5y2m15d) tried this activity this morning. It is a little too easy for him, although I think it is good practice to burn the logic of addend plus addend equal sum into his memory. We used double digits sums to make it more challenging. Here I am using Lego number blocks instead of number cards: