Step 1: Fold the longest edges of the paper together. Then open it out. 
Step 2: Fold the corners into the first fold. 
Step 3: Fold the paper in half along the first fold. Then fold in half again lengthways. 
Step 4: Open out the second fold. 
Step 5: Fold down the two sharp corners. 
Step 6: Fold the paper back along the second fold to make a triangle shape. 
Step 7: Grip the banger firmly by the two sharp corners. Flick it down quickly- and it makes a loud bang.How a paper banger works
The air is pressed inside during moving the paper banger downwards and the air suddenly is free when the inner layer is coming out. It is a small explosion. It is very similar to the way thunder sound is created.
Lesson Plan
Extended Resources
1. For more information on sound (Kayla and LaToya's project)
2. Science of Sound(Wired@School)
3. More fun with sound(University of Rhode Island)
