Zero Sum
WorkingFind runs of numbers that add to zero before the sixty seconds run out
What it's for
- practise quick mental arithmetic against a clock
- play a short number puzzle between tasks
We have checked Zero Sum 152 times since 15 Sept 2026, and it answered every time. Its visible text has not changed since we started watching.
What it does
A timed maths puzzle on a grid of numbers. Click a number to start a sequence and extend it through adjacent tiles, scoring when the sequence sums to zero — longer sequences are worth more. You have sixty seconds. There is a dark theme and a choice of click or drag highlighting, and the source is on GitHub.
Others that do this
Each answered its most recent check.
Looking for something else?
What stands out
- No account required
- Free
What we checked
App accessible
The last check reached a working page.
Page rendered
The last browser pass found a page that rendered.
Screenshot kept
We captured a picture of the page.
Looked at by an agent
An agent reviewed it. That is not a person.
- Looked
- 0
- Opened
- 32
- Checks
- 152
- Watching
- 0
0 browsers
32 browsers
152 checks
Nobody yet
Browsers on this site, not verified people.
Evidence
Each bar is one request we made- Checks
- 152
- Working · last 40
- 100%
- Median response
- 336ms
- Watching since
- 15 Sept 2026
Of the last 40 checks, 40 answered (100%); the latest was on . Median response 336 ms. Watching since .
Browser render check
Checked 1 month ago in a real browser1 page rendered
Activity
Watching since- Last content change
- None seen yet
- Unchanged for
- 47 days
- Certificate expires
- in 58 days
How it looked
1 month ago
1 month ago
- The TLS certificate was renewed19 days ago
- Its embedding policy changed1 month ago
What people say
No reviews yet.
Embed this status
For a README. It updates on every check.
[](https://itstillworks.app/verify/zero-sum)