Light Bulb Moment
Eight bulbs. One target. Can you think in binary?
Turn the right lights on and off to match the number.
How It Works
Imagine you need to send a number using only light bulbs that can be turned ON or OFF.
With 1 bulb you can show 2 states: 0 (off) or 1 (on).
With 2 bulbs you can show 4 states: 00, 01, 10, 11.
If we treat these as place values, 10 means “one two” = 2, and
11 means “one two + one one” = 3.
With 8 bulbs you get 256 unique states — enough to represent every integer from −128 to 127. This app uses two’s complement encoding, the same scheme real CPUs use:
Value = −128×b₇ + 64×b₆ + 32×b₅ + 16×b₄ + 8×b₃ + 4×b₂ + 2×b₁ + 1×b₀
The leftmost bulb (highlighted in red) is the sign bit. When it is ON, it contributes −128 to the total. That single negative value can pull the whole result below zero.
- Press Go! — the computer picks a random target in [−128, 127].
- Click individual bulbs to toggle them ON (yellow) or OFF (grey).
- Use All On or All Off to bulk-reset (each counts as one click).
- When your binary value matches the target, you win! ✔
- Your results are logged below. Copy & paste into a spreadsheet to track progress over time.
Pro tip: The minimum possible clicks is shown after each win.
A Click Score of 1.000 means you found the optimal path. Can you beat the computer’s ideal?
Want to play again? Just press Go! at any time after a game ends.
Eight Bulbs, One Target
| 27 sign | 26 | 25 | 24 | 23 | 22 | 21 | 20 |
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Results History
Copy and paste this table into a spreadsheet to track improvement over time.
| # | Target | Binary | Clicks | Min Clicks | Score | Time |
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