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V

Forecast

The Number

Put a number on something nobody knows yet, and say how sure you are.

Time
~45 min
Team
Any number of teams
Format
Commit, then a staged reveal
Level
No prereqs

What students do

Each team gets a brief of ordinary facts and one question that has a real answer: what the cart takes on its first morning. They break the number into three components, source each one, estimate, and give an honest range. Then pens go down and a tear-off strip goes to the front, and nothing changes after it leaves the table. The facilitator reveals the components one at a time, then the headline, then the leaderboard. Because half the score is read off a printed band table rather than judged, one facilitator can run this for a room of any size.

The skill it builds

Estimation under uncertainty. Decomposing a number you cannot look up, committing to it in public, and stating a confidence range that can actually be checked.

The one idea that makes it teach

Say how sure you are.

A beginner either gives one number and defends it to the death, or refuses to give one at all. Both are failures. The scoring rewards a range that is narrow where the team had evidence and wide where it did not, so a confident wrong answer loses to an honest one, and a uselessly wide hedge loses too. That is the habit every budget, forecast and business plan depends on.

  • Break it into threeA number you cannot estimate is three numbers you can.
  • Commit in writingThe strip leaves the table. Nothing changes once the reveal starts.
  • Be honest about the rangeNarrow where you had evidence, wide where you guessed.
How it's scored

Fair, and the same shape every time.

Four criteria, 25% each. Accuracy is objective, read off a band table, so a team's score does not depend on which judge walked past.

Accuracy25%

How close the headline lands, read off the band table.

Calibration25%

An honest range: narrow where they had evidence, wide where they did not.

Decomposition25%

Three components, each sourced, the arithmetic reconciling to the headline.

Sensitivity25%

The one assumption the answer hangs on, and what evidence would settle it.

The worlds

Six built, four designed

The Opening Day
A juice cart's first morning on a new corner, with a second variant so two sections can run it in one week.
Built
The New Machine
Every number is printed in the packet, and the answer still cannot be multiplied out of them.
Built
The Fifty Cents
A price rise, an old price test, and one idea from economics. Revenue falls; profit rises.
Built

Bring the five to your classroom.

Decide · Investigate · Negotiate · Respond · Forecast

Request a sample packet and a run-through of any program. One class block is all it takes to see it work.