Students test from how far away each kind of magnet can attract a paperclip.
Lay the thick paper/card over the magnets.
Pile the pins or shapes onto the card, and arrange.
They can see how tall they can build the sculpture/what shapes they can make etc.
Remove the backing from the contact paper and tape it, sticky side up, to the table in front of a student.
Students stick hexagons of tissue paper to the contact paper, arranged as a honeycomb (or not). Tell them that once the tissue paper touches the contact paper it is impossible to get up again without tearing it.
It can be hung in a window as "stained-glass" art.
Optionally eat honeycomb, and talk about what students know about bees.
Ideas for conversation:
Look at honeycombs. What repeating shape can you see in the honeycomb?
Taste the honey. What do bees make honey from? [flower nectar]
Chew the honeycomb. Where does the wax come from?
Why do bees make honey? [it is food for their young]
Student groups rotate through three or four activities.
Follow with discussion about each activity.
Some mail order websites for red wiggler worms (search "Red Wiggler" to find others):
http://urbanwormwonders.com (Mission, BC)
http://worm-composting.ca (Chilliwack, BC)
https://www.burnabyredwigglers.com (Burnaby, BC)
https://wormworx.ca (Burnaby, BC)
Apparently 500 worms in a pound.
The worms are not cheap: over $40 for half a pound, but red wigglers do well in indoor compost bins.
The alternative is to collect small garden worms, from a compost or garden soil. Avoid the large ones.
Do each challenge in turn.
I also added in a pulley challenge: students were given two pulleys and a long length of rope, and asked to make a pulley system to move a bag from one end of an area to another. They worked together, with help from me, to understand how a simple pulley works.
Use playground equipment, discussing each in terms of the forces and energy.
Play tennis or another sport, to explore the forces in a lever.
Bounce balls and learn about the energy transfers.
Distribute a jar of water and a couple of pieces of pottery to each pair or small group of students.
Explain that they will mimic the way that flowing rivers and the rain interact with the rocks on mountains.
Ask students to add their pottery pieces to their jar and screw on the cap. The pottery pieces are rocks.
Ask students to vigorously shake the jar. They are mimicking water and wind bashing the rocks, and wearing them away - the process of weathering. With the pottery, the pieces are broken into smaller particles much much faster than most of the natural weathering of the harder rocks of mountains.
Students look inside their jar to see that they have made smaller particles from their rock, then draw what they see. The left side of the second page of either attached worksheet can be used.
Explain that as rocks are worm away, they make sand and mud particles. Sand particles are larger and mud particles are smaller. The particles are washed into streams, then rivers, then the ocean. In the ocean they are carried by the currents until they are deposited in a calm shallow bay. Over a long time, a sand and mud beach is made, and continues to be built upon.
Optional: compare chalk and granite gravel. Do they break apart more quickly or slowly than the pottery.
Try chemical weathering with a dilute acid over several days. Vinegar and chalk.
TeachEngineering activity: Rocky-to-Sandy Beach: A Weathering Model uses candies of different kinds and sugar cubes to show weathering.
Do the activities in order.
Show the students a photo of a bridge or other man-made structure. Point out the shapes made by the steel girders (e.g. triangles in the Burrard Street Bridge, diamonds and rectangles in the Port Mann Bridge). Explain that the shapes are made during construction to make the structure as strong as possible. Tell the students they will be testing different shapes for their strength.
Show the students how to make a triangle and a square from a sheet of paper and tape, how to lay a platform between two identical shapes, and add a load to the platform. Do not reveal what will happen.
Students make two identical triangles and two identical squares by folding a letter sized sheet of paper and taping it closed with pieces of masking tape. If there is time, they can also make two of another shape that they choose (e.g. circle, pentagon). This requires some skill to accurately assess where to make the folds, and to tape the edges together so that there is no overlap. If the students are unable to do this accurately, the teacher should do it for them.
Students test the strength of each shape by laying a cardboard platform between two of the same shape, adding a small container to the centre of the bridge, then adding pennies to the container until the shape starts to collapse or distort.
Students record the number of pennies added to a shape before it distorts or collapses. (See the attached worksheet).
As a class, add all results to a class graph, with number of pennies up the side of the graph and the shapes along the bottom, and find out which shape is the strongest. It is expected that the triangle would be the strongest (see image for one class' results).

(This graph is a good opportunity to show students that sometimes data is a little messy, and one might need a lot of data points before seeing a pattern emerging.
From one group’s results, it might not have been clear which shape was the strongest, but when everyone’s results are graphed together, a pattern emerges: the triangle is clearly stronger than the other shapes. There is not enough data here to determine if the square or circle is stronger.)
Explain why the triangle is the strongest shape: the sides of a triangle are a fixed length, so as a force is applied the angles of the triangle cannot change, so maintaining the triangle’s shape. A triangle will fail when either the sides buckle (as probably happened in this experiment), or when the joints break apart. When a load pushes down on the triangle, the two top sides are under compression as the force from above pushes down on them. The bottom side is under tension as the ends are pulled apart. (So in construction the bottom side that only experiences tension can be made of a lighter material than the upper two sides that must be more rigid to stand up to compressive forces). In the case of the square, the angles can change even when the length of the sides stays the same - it is easily pushed into a diamond shape.
It was challenging for some grade 2s to make the shapes accurately enough to really compare them - sometimes the sides didn't meet, or overlapped, or the tape was reinforcing sometimes. Need to try it with older students to see if it is a viable activity.
Better activity with the same concept (though way more prep) is Building sturdy structures