To build a toothpick bridge, make the required number of planks, each containing two toothpicks, and join them to form the bridge's top and under sides using wood glue. Affix toothpicks across the bridge's top layer, attach this layer to the bottom one, and position toothpicks appropriately to secure the structure.
To make one plank of a toothpick bridge, place two toothpicks with their opposite ends positioned side-by-side on the working area, and attach using glue. Make 200 planks in this manner. Apply glue to approximately one-third portion of one plank's top from one end, and affix another plank on this area. Join around 30 planks in this manner. Repeat this step to form three more plank lengths, each containing 30 planks.
Place two of the four plank lengths side by side. Lay two toothpicks at the ends of the planks and in between the lengths to separate them. Apply glue on the toothpicks' ends, and attach the two plank lengths to them. Now, stick the inner edges of the two lengths at their center to form the bridge's bottom side.
Next, place the other two plank lengths side by side, and glue toothpicks across the lengths, leaving a gap of about 1 inch. Apply glue on the tips of the lengths, bend them and attach to the bottom side's edges. Affix toothpicks between the bridge's bottom and top sides to keep the project in place.