## Saturday, 30 November 2013

### Montessori Activity: Constructive Triangles - Triangle Box

Age: From 4 years old

Objectives:
1. To show the child that the different triangles all make up an equilateral triangle (i.e. a triangle with 3 equal sides.)

2. To prepare the child for geometry.

Materials:
1. The Montessori Triangular Box
2. 1 mat

Directions:
1. Show where the triangular box is kept and bring it to the mat.
2. Take all triangles out and spread them out randomly on the mat.
3. Show the child the gray triangle, let him feel it and say, "this is equilateral triangle i.e. a triangle with 3 equal sides (等边三角形)."
4. Tell the child that "I am going to build the triangle like this gray one."
5. Take out 1 green triangle put it in front of you.
6. Take out the other green triangle and slide it into the previous one by matching the black line together.
7. Match the 2 yellow isosceles triangles (等腰三角形) (i.e. 2 equal sides triangles) by the black lines.
8. Match the 4 red small equilateral triangles by the black lines.
9. Mix all the triangles up again and encourage the child do it.
10. Show the child how to place the triangles back into the box in the correct order: red triangles, yellow triangles, green triangles and the gray triangle.

Video Demonstration:

Control of Error:

If the newly-constructed figures are not constructed with matching black lines and if they do not match the gray triangle.

Language:
Talk about equilateral triangle and isosceles triangle.

References:
Basic Montessori Learning Activities for Under-Fives by David Gettman
http://faculty.fullerton.edu/syen/mts/sensor/12.htm
http://www.infomontessori.com/sensorial/visual-sense-constructive-triangles-triangular-box.htm
http://www.mathsisfun.com/triangle.html

You can find the Montessori triangle box from amazon: 28 Nov. 2013 - 4Y8M25D