This game is great to do on a playdate or family day. Kids will learn about what makes things float and sink, practice counting, and use creativity and fine motor skills.  Younger preschoolers may need assistance with the initial construction piece, but all ages (moms and dads too!) will have fun building and sinking their boats (see NOTE below)!

LEARN SCIENCE VOCABULARY:

Buoyancy – the ability to float in liquid.

Buoyant force – the upward push of the water on the boat.

MATERIALS NEEDED:

• Aluminum foil
• Pennies (a whole bunch, so dig through the center console in your car and the bottom of your purse. When my husband did this with the kids, he used all types of coins and took the opportunity to teach about differentiating money!)
• Large bin, water table or kiddie pool filled with water
• Pen and paper to keep score

  

HOW TO DO IT:

1. Give each person equal size squares of aluminum foil.
2. Everyone should build a boat that they think will float in water and can hold a cargo of pennies. (Most kids over 3 should be able to manipulate the foil, but some may need help remembering what a “boat shape” looks like.  I would suggest making an example and having them recreate something similar. Although my 3-year-old kept insisting his was a Dump Truck.)

   

3. When everyone has constructed a boat, place them in the water.  (Hopefully they will all float while empty.  If not, they could get a free do-over…it’s a friendly competition, after all!).
4. Now add a penny to each boat. Does it remain BUOYANT?
5. Keep adding pennies one at a time to each boat, counting each one as it goes in, until all boats have sunk.  Each time someone’s boat sinks, everyone shouts “Titanic!”

   

6. Pull each boat out of the water and count how many pennies they had.  Kids with writing skills can keep track of the score/data (in this case, number of pennies each boat held before sinking) on a simple chart.
7. Give everyone a chance to redesign their boat and play the game again (until you get tired of it or everyone is soaking wet)!

NOTE: Younger toddlers can still play and learn with this activity!  While you can skip the “game” aspect of it, they can practice fine motor skills as they drop pennies in and sink their boats.  Hearing you count aloud each penny will help introduce math and reinforce verbal skills.  My 18-month old was seriously into it and wanted me to set up her boats again and again!

THE SCIENCE BEHIND IT:

Archimedes, an old Greek guy from long ago, famously overflowed his bathtub when he climbed in and shouted “Eureka!” upon discovering Archimedes’ Principle of buoyancy (probably named after the fact).  Why he filled his bathtub so full we may never know, but because of this bathroom incident we do know why giant steel cruise ships float in the water.  The BUOYANT FORCE of the water pushing up on boats is equal to the weight of the water that is displaced by them.  In other words, boats take up space in the water, and water pushes up on them with a force equal to the weight of that volume of water.  And as anyone knows who has dragged a bucket around to mop the floor, water is quite heavy (5 gallons weighs over 41 lbs!). The buoyant force pushing up on large cruise ships is about 50,000 tons!