Here's a great way to stay cool this summer and slam your mates!

What you'll need:

• Piece of square paper
• Your fingers

How to make it:

1. Fold the paper in half from A to D. Press on the fold to make a good crease. Then unfold.
   
   
2. Do the same with B to C.
   
   
3. Turn paper over, fold C to A (D to B), unfold and turn back over. Pull points E and F down to G and flatten to make a triangle.
   
   
4. Fold bottom corners H and I up to point J.
5. Turn the paper over and repeat Step 4.
6. Fold the top of the triangles K and L into point M.
   
   
7. Turn the paper over and repeat Step 6.
   
   
8. Fold the bottom flaps into the gaps in the middle pieces. Turn over and repeat.
   
   
9. Blow into the hole at the top to inflate.
10. Cut a bigger hole at the top to fill it with water.
11. Time to Push Play and throw some bombs!

Tip: Don't put water in it and you've got yourself a hacky sack - nice one!