Size It UpDaily

How long can your number sense last?

Size It Up: Survival

Ten lives. Fifteen seconds per question. Keep your estimates within the right order of magnitude.

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Today’s challengeRound 1 of 5
0 / 500

How large is the target compared with the reference?

Navy stays fixed. Resize red.

Two labeled objects appear on a shared baseline. Adjust the target object until its displayed size matches its real-world scale relative to the reference.

The fixed reference is on the left and the resizable target is on the right. Use the scale control or arrow keys, then lock in your estimate.

1x

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The game in focus

How to play Survival

A tenfold miss costs one life; a hundredfold miss costs two. The timer pauses at the answer so you can understand the result, then starts again when you continue.

One run is saved per browser each week. A new Survival run opens on Monday at 00:00 UTC. Leaving during a timed question does not freeze its clock. Measurement notes →

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