Canadian Icicles
These are very pretty, and quite simple to make.  The integration possibilities are (Math - Geometry) 2D and 3D shapes (Science - *Color).   
Here's what you need:

1.  red pipe cleaners

2.  Borax detergent

3.  boiling water

4.  2 litre milk cartons with the tops cut off (one per child)

5.  bamboo skewers

6.  fishing line

 

 

Here's what you do:
1. Using 3 to 5 pipe cleaners, intertwine them to achieve the desired 2D or 3D shape.
2. Tie a piece of fishing to your icicle.  (The string should be long enough so that the icicle can be completely immersed in the Borax solution in the milk carton.)
3. Mix 3 TBSP of Borax for every 2 cups of boiling water. (Be sure that the Borax is completely dissolved.)
4. Pour the Borax solution into the milk cartons.
5. Hang the snowflake by the fishing line to the bamboo skewer
6. Totally immerse the snowflake in the Borax solution, with the bamboo skewer resting on top of the milk container.
7. Let the snowflakes stay in the Borax solution for at least 3 days.  The longer they stay, the better the crystallization.
8. Once you have achieved crystallization, carefully hang the icicles in the window.  They make beautiful sun catchers.  *If you are using this for a Science activity, white pipe cleaners work better for achieve a prism effect.
This project is presented by Mrs. Ewasiuk's Grade 1A class and Mary Hanley Catholic School.