Toddlers can answer classification questions, such as “What shape is this?” by either pointing to, tracing or saying the names of shapes seen in pictures or 3D models of bridges.
Toddlers can touch the paper, paper clips, and weights. Children this age can think about what these materials are typically used for and where they have ve seen or used the materials before.
Toddlers can also talk about where they’ve seen bridges before and what bridges are used for.

Some toddlers may want to try to make a copy of another child's paper bridge and do their own testing. Younger toddlers may prefer to test a paper bridge that someone else made.
Toddlers can be encouraged to set a goal before testing a bridge (e.g. "I want my bridge to hold 5 turtles") - this will give toddlers something to work toward in their designs.
Toddlers can practice ripping paper, or cutting paper with scissors, while they work to construct their bridge.
Toddlers can also work on their paper clip skills (grownups can help by showing them how to use a paper clip, starting the paper clip for the child and then letting the child push the clip on).
Toddlers can also work on rolling and folding paper into new shapes, or crinkling and then smoothing their paper, to see if that makes it stronger.