Montessori Activity: Deciphering Between Sizes with the Red Rods or Rainbow Lego Rods

Age: From 2.5 years old (Level 2)

Acitivity Duration: 10 minutes

Objective(s):
1. To teach the child to decipher between sizes.
2. To indirectly prepare the child for later work in geometry through the general observation of the geometrically regular differences in the rod's length.
3. To indirectly prepare the child for the concept of numbers by demonstrating the unit difference in length between the 10 successively longer rods.

Material(s):
1. The Red Rods or in my case, the Rainbow Lego Rods
2. A floor mat or a tray.

Directions:
1. Arrange the rods in a random order on a tray/floor mat, so that your child can see them clearly.

2. Put the rods horizontally to the right of you and ask your child to sit on your left.

3. Tell your child that you are going to build the rods into a staircase starting with the shortest. select the shortest rod and put it in front of you. When you are selecting your rod, run your right hand along to the end so that your child will see that you are finding the next length.

4. Build up the rest of the staircase, finishing with the longest rod. Take the opportunity to introduce the mathematical language of long and short.

5. Tell your child that you are going to dismantle the staircase so that he can build it.

6. Take the rods one at a time and place them to the right of your child in a random order.

7. Invite your child to build the staircase.

Video Demonstration:
http://www.youtube.com/watch?v=gEK6sfGQkIE

http://www.youtube.com/user/AtHomeMontessori#p/a/u/1/ILKLhXa2mjc

How to Make the Rainbow Lego Rods?
1. 10 rods from 1 brick as Rod 1 to 10 bricks as Rod 10.
2. For each rod, choose a different Lego colour bricks.

Cost:
Cost of the real stuff: 46 USD from http://www.bambini-montessori.com/price_list.htm, since I made it with the Lego I have at home, the lego bricks were a sunk cost.

Additional Information:
I posted a post on making the Red Rods wtih red cardboard. This is another way of making the Red Rods using the Lego bricks. It is actually more suited to call it the Rainbow Lego Rods.

References:
http://www.infomontessori.com/sensorial/visual-sense-red-rods.htm