Finding Zero

Every number turned over says how far zero is, so the hunt closes in by reasoning rather than guessing.

The Finding Zero board

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Grades
1–6
Subjects
Counting & Estimating, Adding & Subtracting, Logic
Kind
Game
Cost
Free, no account, no ads

What it is

Every square on the board is face down, and one of them is 0. Turn a square over and the number on it says how many steps away 0 is — not which direction, only how far. The numbers lie in order along a closed path, so 35 can be one step from 0 rather than thirty-five, and nothing on the board is ever more than half a lap away.

The rules

Every square is face down and 0 is hidden among them. Five squares are turned over in turn — 18, then 9, 4, 2 and 0 — each one nearer than the last, and the board runs from cold blue to hot red as the hunt closes in.189420
Click on the dots. Try to find zero.

What it gives you to practise

Almost no arithmetic. What the board asks for is the use you make of an answer you already have: a high number means look somewhere else, and two low numbers with a gap between them pin the loop down. In the blindfolded packs the path itself is hidden, so the only map is the one built out of taps already spent. The race packs price a tap at three seconds, which turns the same question into a different one — is this tap worth what it costs?

In a classroom

A good first conversation about searching. Put two children on one board taking alternate taps and they will start arguing about where the next one should go, which is the whole lesson; the board is just the referee.

Share or embed

The whole game at one address, with every board in it. Whoever opens it stays inside it, and their progress stays in their own browser.

Play Finding Zero

Near it on the shelf