## Wednesday 10 September 2014

### Montessori Activity: Static Subtraction with Golden Beads - Hundred Place Value (减法[jiǎn fǎ])

AGE: From 5.5 years old

OBJECTIVE(S):

To teach counting and subtraction of the hundred 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
- Subtrahend (减数 [jiǎn shù]): the second number in a subtraction (the number to be subtracted)
- Difference (剩[Shèng])

MATERIALS:

2. 9 ten-bars
3. 9 hundred-squares
4. 1 static subtraction worksheet
5. 3 felt pieces
6. 1 pencil and eraser

PRESENTATION:

1. Arrange the work as shown above.

2. Say, "Today we are going to learn how to take away large numbers."

4. Point to the unit place value listed in the minuend on the worksheet and ask, "How many units are there?" Your child should answer 3.

5. Take this amount of golden beads and place them on the felt piece to the right of the worksheet.

6. Next point to the ten place value of the minuend and ask, "How many tens are there?" Your child should answer 2 tens.

7. Take 2 ten-bars and place them on the felt piece to the right of the worksheet.

8. Next point to the hundred place value of the minuend and ask, "How many hundreds are there?" Your child should answer 3 hundreds.

9. Take 3 hundred-squares and place them on the felt piece to the right of the worksheet.

10. Point to the unit value of the subtrahend and ask, "How many units are there?" Your child should answer 1. Remove the 1 unit bead further down on the felt piece on the right.

11. Point to the ten value of the subtrahend and ask, "How many tens are there?" Your child should answer 1 ten and remove a ten-bar further down the felt piece on the right.

12. Point to the hundred value of the subtrahend and ask, "How many hundreds are there?" Your child should answer 2 hundreds and remove 2 hundred-squares further down the felt piece on the right.

9. Count the remaining beads on the top of the right felt piece, write the answer in the worksheet and read it out, for e.g. 323-211=112

10. Repeat this process with other subtraction problems.

Note: Make sure that the worksheet you use contains only static subtraction, i.e. does not contain 3 minus 4, etc. as otherwise the beads would not work.

VARIATIONS:

1. Try with vertical presentation of the equation.

J (5Y6M6D) tried this for the first time on 11 Dec 2014, and he could do it without any problems.

REFERENCES:

Brilliant Mind Montessori

 11 Dec 2014 (5Y6M6D) - J trying out for the first time and could do it without problem.

Brilliant Mind Montessori is available from Amazon: