Ancient Number

Choose this exercise

Purpose: Identify unstated assumptions and test hypotheses without spoiling puzzle solutions for others.

Use it when: Use during a workshop warm-up or transition to explore how focal cues mislead attention.

Skip it when: Skip when participants dislike parlor riddles or when sightline constraints prevent viewing subtle hand cues.

Group arrangement: Whole group facing a shared table surface or overhead camera stream.

Timing: UWT suggested 12 minutes based on the source 5 to 15 minute band.

Materials and tools

• 5 to 10 straight items such as craft sticks, pens, or flatware
• 1 flat table or tray visible to all participants

Before participants arrive

1. Arrange chairs in a semicircle so every participant has a clear sightline to the table surface.
2. Place the sticks in a loose pile within reach.

Say this to open

I will arrange these sticks on the table to show numbers from an ancient counting system. Your task is to figure out the code. When I finish an arrangement, anyone can guess the number. If you think you cracked the secret rule, do not blurt out the explanation. Instead, prove it by naming the correct number or laying out your own stick arrangement and giving the right answer.

How to run it

1. Introduce the challenge 2 minutes

   Speak the opening script. Emphasize the core rule: participants may call out guesses, but they must never explain the underlying mechanism out loud. Confirm everyone can see the tabletop clearly.

2. Run test rounds 4 minutes

   Make an intricate stick pattern. As you finish, rest fingers visibly on the table edge, such as three fingers. Announce: 'This is three.' Clear the sticks. Make a shape using seven sticks while resting one finger. Ask: 'What number is this?' Collect quick guesses. If people count sticks, reply: 'No, this is one.' Run fast rounds with varying shapes and finger counts from zero to five.

3. Verify participant hypotheses 3 minutes

   When a participant gets two consecutive numbers right, invite them to demonstrate a new arrangement or verify the next round without revealing the trick. Continue testing new arrangements until several participants catch on or time expires.

4. Reveal and debrief 3 minutes

   If the secret remains hidden, reveal the mechanism by pointing directly to your resting fingers. Ask the debrief questions. Collect two or three brief reflections from the group on how their attention was directed.

Debrief questions

• What assumptions kept your attention locked onto the stick patterns?
• What first caused you to widen your focus beyond the sticks?

Finished output: Group discovery of the hidden finger-cue mechanism, or a facilitator reveal closing the puzzle.

Remote

Point a downward-facing webcam at the desk surface. Ensure the camera frame captures both the stick arrangement area and the table edge where your hands rest. Participants submit guesses via public chat or unmuted microphone.

Hybrid

In-person and remote participants observe a single overhead desk camera stream projected in the room and shared on screen. Remote and room members call out or type guesses equally.

Access and participation choices

• Participants may observe quietly and test hypotheses mentally without voicing guesses.
• Provide a high-contrast desk surface under the sticks and hands to assist visual clarity.

If the session gets stuck

A participant blurts out the solution and spoils the puzzle.

Acknowledge the discovery, change the cue to something else subtle such as hands placed flat versus fists, and run another round.

The group becomes stuck and frustrated after several failed rounds.

Exaggerate hand placement slightly by tapping the resting fingers deliberately on the table surface after arranging the sticks.

Terms used here

• Distractor: An irrelevant detail placed deliberately to draw attention away from the true signal.