Whole Group Activity
Which form is stronger?
Explore with a sheet of paper the strength of accordion-pleated sheets compared to simple folded
sheets.
Materials:
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Two identical sheets of paper
Pennies
Notebook
Fold one sheet accordion-fashion along its length and make a bridge between two books.
Fold the other in half lengthwise, then again in half lengthwise. Be sure the two papers are the
same length. Make this paper bridge two books.
Working in pairs, have one student add pennies one by one to the bridges; have the other student
record the number of pennies added before the bridges collapse. Which folded shape is stronger?
Extensions:
Self and Society
Visit a bridge near your school. Discuss what the cars, trucks and pedestrians would have to do if
the bridge were not there. What shape is the bridge? What does it cross over? Of what material is
it made? When the children return to school, have them draw the bridge from memory, or have
the class create a river mural with many bridges.
Language
Discuss with the children the different types of bridges and the different parts of a bridge:
arch
curved structure, support for bridge, roof or floor
force
any action that tends to maintain or alter the position of a structure
beam
long piece of squared timber or of metal, supported at both ends
cantilever
beam or girder fixed at only one end
span
the stretch from side to side, or end to end
pier
support of arch or of span of bridge
girder
structure or beam of steel forming span of bridge
truss
supporting framework of bridge, often formed of triangular braces
suspension bridge
roadway is hung across river on wire or chain cables passing over towers and anchored, without
support from below
trestle bridge
bridge supported with open braced framework of wood or metal or concrete
Ask the children to name all the materials that they have seen in a bridge: wood, steel, concrete,
stone.
Talk about bridges that open: swing bridges, drawbridges and lift bridges. Discuss the obstacles
bridges cross: rivers, roads, ravines.
Discuss the difference between a bridge and a dam; a tunnel; a causeway; a viaduct*; an
aqueduct*.
*Viaduct: a series of arches making a long, bridge-like structure.
*Aqueduct: a series of connecting bridges topped with a trough to carry water across a valley.
The Three Billy Goats Gruff
Primary children may enjoy this activity. Read this wonderful tale about crossing a bridge to
your students. The original author was Peter Christen Asbjornsen, but the tale has been retold by
Rounds, Glen. The Three Billy Goats Gruff. New York: Holiday House, 1993.
The Arts
London Bridge
For primary students, teach the class "London Bridge is Falling Down," and play it as a singing
game, two children making the arch, the rest filing through. When all are through the arch, the
first two children through the original arch make a new arch.
The words can be found on the activity sheet, London Bridge
Whole Group Instruction: Fold 3 similar sheets of paper in each of the ways described below.
Lay each piece of folded paper across two piles of books and find out which one supports the
most weight. You can use pencils as weights.
1. Fold the paper up at the edges to make guardrails along your bridge.
2. Fold the paper like a fan. Press the creases tightly and lay the paper so the creases run
from one pile of books to the other.
3. Fold the paper to make a box shape. Tape the sides together and lay it like a covered
bridge across the gap between the books.
Which paper bridge is the strongest?
Station 1: Shifting Shapes
Distribute 10 toothpicks to each student. Ask them to create triangles with three toothpicks,
squares with four, pentagons (5), etc., working through hexagon (6), octagon (8), to decagon
(10). Have them count the number of sides and the number of angles in each shape as they go.
What happens to the size of the angles as the number of sides increases? With more toothpicks,
have them try making triangles in the larger shapes.
For Early Finishers:
Name that Bridge
Print the name of the type of bridge below its picture.
1) _______________________
2) _______________________
3) _______________________
4) _______________________
beam
arch
suspension
cantilever
Circle the strongest shapes below.