Paper span-load trial
Compare supported beam shapes while fixing span, paper and loading position.
Adult planning suggestion: about6–9 · Shape & spatial thinking
- Players
- 3–4 per group
- Time
- 20–30 minutes
- Materials
- Two 180×60mm equal-paper strips, two low supports, ruler and ten equal light counters.
Prepare
Use two equal 180×60mm strips cut by an adult from the same paper. Put two equal low book supports 100mm apart on a table; each strip overlaps 40mm at either end. Keep supports low so a falling light counter stays on the table. Predict before loading; never put a person or heavy object on the bridge.
Play
Test one flat strip and one accordion-folded strip. Fold the second along its length at 10mm intervals across the 60mm width; the 180mm bridge direction stays unchanged. Add identical light counters at the same central location, one at a time. Stop at collapse, slipping from a support or ten counters, whichever comes first.
Worked example
Record the last successfully supported count and the reason for stopping. If the flat strip holds 2 and fails at 3, record 2 rather than 3. This is an example of logging, not a promised result. A strip that holds all ten is recorded≥10, not as a measured failure capacity of exactly 10.
Finish and check
Remove loads before changing shape. Repeat with fresh equal strips if making a comparison across groups, or explicitly record reuse and creases as a limitation. The task is complete when both trials and controlled variables are recorded, even if the folded strip does not outperform the flat one.
Adaptation and limits
For thirty learners use ten trios and enough adult-prepared strips. Rotate loader, observer and recorder. Hand-copy the dimensions instead of printing if needed. The source explains folded paper beams; actual strength depends on paper, fold quality and loading, and this activity has not been physically tested by this page’s author.
Purpose, observation and provenance
Within this activity: Compare supported beam shapes while fixing span, paper and loading position.
Ask whether paper, support span and load position were held constant and separate observation from prediction.
Our rules, examples and printable diagrams are separately prepared. The earliest inventor of the broader mechanism is not established here.
ANU — Paper Bridge Challenge — Folded-beam investigation background; our dimensions, ten-counter ceiling and record sheets differ.
Age bands are planning suggestions. Goals describe observable actions, not measured long-term gains or institutional endorsement.
Free alternative: Copy the supplied grids, labels and cards onto reused paper. No specialist product is needed. Adults may prepare pieces or act as a scribe.
Printable materials
Preview at 100% scale, with browser headers and footers off. Cut with suitable help. Keep host keys separate. This is a manual tabletop kit, not an online opponent, automatic judge or solver.
Player materials · Paper span-load trial
Strip 180×60mm; support overlap 40mm at each end; gap 100mm.
Flat/folded / last supported / stop reason / same paper,span,load?
Two strips below, each180×60mm at100%. Supports overlap40mm at both ends. Solid outer line: cut; dotted inner lines: fold on the second strip only.
Player record · keep host key separate
| Shape | Last supported | Stop reason | Controls |
|---|---|---|---|
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
| ________ | ________ | ________ | ________ |
Host key · separate from players
No fixed experimental answer. Record last held count; all ten held means≥10. Only shape should change in the primary comparison.
Run the round
Use two equal 180×60mm strips cut by an adult from the same paper. Put two equal low book supports 100mm apart on a table; each strip overlaps 40mm at either end. Keep supports low so a falling light counter stays on the table. Predict before loading; never put a person or heavy object on the bridge.
Test one flat strip and one accordion-folded strip. Fold the second along its length at 10mm intervals across the 60mm width; the 180mm bridge direction stays unchanged. Add identical light counters at the same central location, one at a time. Stop at collapse, slipping from a support or ten counters, whichever comes first.
Record the last successfully supported count and the reason for stopping. If the flat strip holds 2 and fails at 3, record 2 rather than 3. This is an example of logging, not a promised result. A strip that holds all ten is recorded≥10, not as a measured failure capacity of exactly 10.
Remove loads before changing shape. Repeat with fresh equal strips if making a comparison across groups, or explicitly record reuse and creases as a limitation. The task is complete when both trials and controlled variables are recorded, even if the folded strip does not outperform the flat one.
For thirty learners use ten trios and enough adult-prepared strips. Rotate loader, observer and recorder. Hand-copy the dimensions instead of printing if needed. The source explains folded paper beams; actual strength depends on paper, fold quality and loading, and this activity has not been physically tested by this page’s author.
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