Building marshmallow bridges is a fun and educational craft project that young students will adore. The activity is low cost and easy to clean up afterward. Because marshmallow bridges can be constructed in many different ways, children and teens will enjoy trying to build the best possible bridge with the given materials. This project can be undertaken in the classroom or at home, alone or with friends.
Gather together your marshmallows and toothpicks. Pick the gap that you plan to build your bridge across. Make sure that the gap isn’t too large and that the objects on the two sides of the gap are sturdy. Make sure, also, that the toothpicks are strong, and the marshmallows are fresh, miniature marshmallows.
Spear one end of a marshmallow with a toothpick until it comes to rest in the middle. Place another marshmallow on the other end of the toothpick; continue to add toothpicks and marshmallows in a straight line until you decide that the bridge is adequately wide. Place the row of marshmallows near the back of the top surface of the object on one side of the gap.
Add more toothpicks and marshmallows to the first row of marshmallows to create the first layer of your bridge. Form either squares or triangles with your materials on your way to the other side; experiment to see whether one is more stable than another. Continue building the first layer of the bridge until you reach the other side of the gap; the beginning and ending rows of marshmallows should more than span the opening. Construct a mirror image of the first anchoring marshmallows and toothpicks and set the row of marshmallows down on the surface of the other object.
Carefully build the second layer up from the first using the marshmallows and toothpicks. Build up pyramids if your first layer used triangles or cubes if you chose squares. Build the second layer until the bridge is regular, and every marshmallow has at least two toothpicks attached to it.
Add a third layer to the bridge, if desired; only wide bridges can support a third layer, or especially long and sturdy bridges. Place weights on top of the marshmallow bridge to test its sturdiness. Use flat weights, like papers or magazines, in order to distribute the weight over the entire bridge. Build another bridge if the structure falls and try to make a sturdier bridge.
Small children should not use toothpicks without supervision and people of all ages should be careful when handling sharp toothpicks.