Snow

Here's what you need:
  • 1  cup of baking soda
  • 1 cup of shaving cream
  • Bowl
  • Fork
  • Water
Steps: 
  1. In a bowl, add the baking soda.
  2. Next add the shaving cream.
  3. Mix it with a fork.
  4. Add a few drops of water until the mixture takes on a snow-like appearance.
  5. Enjoy!

Paper Roller Coaster

Here's what you need:
  • A4 paper
  • Pencil, ruler and scissors
  • Tape
  • Marble
  • Cardboard to support 
To build a straight segment:
  1. Cut a 7.5 cm (3 inch) wide strip of paper.
  2. Draw two parallel lines that divide it into three 2.5 cm-wide strips.
  3. Fold the two sides up 90 degrees along those lines to form walls.
To build a loop or a hill:
  1. Cut a 7.5 cm (3 inch) wide strip of paper.
  2. Draw two parallel lines that divide it into three 2.5 cm-wide strips.
  3. Make marks every 2.5 cm along the long edges of the paper.
  4. Cut inward 2.5 cm from these marks to form tabs.
  5. Fold the tabs up 90 degrees.
  6. Bend the track into the shape you want, and tape the tabs together to hold it in place. This step is easier with two people, one to hold the track in place and one to do the taping.
To build a curve:
  1. Cut a 7.5 cm (3 inch) wide strip of paper.
  2. Draw two parallel lines that divide it into three 2.5 cm-wide strips.
  3. Make marks every 2.5 cm along one long edge of the paper.
  4. Cut inward 5 cm (2 inches) from these marks.
  5. Fold up the uncut side of the paper 90 degrees to form a wall.
  6. Fold up the tabs on the other side to form the other wall.
  7. Since the bottom portion of the track is cut into segments, you can bend it horizontally to form a curve. Tape the tabs together to hold the curve in place.
To build a support strut:
  1. Cut a 6.25 cm (2.5 inch) wide strip of paper.
  2. Draw four parallel lines that divide it into five 1.25 cm (0.5 inch) wide strips.
  3. Cut inward 2.5 cm along these lines from one edge.
  4. Fold along the lines to form a square shape (so two of the segments overlap), and use tape to hold in place.
  5. Fold the tabs you cut at the end outward. This will allow you to tape the tabs flat to a piece of cardboard, so your strut can stand upright