Operators you will see
2026-03-10 · Arithmetic captchas
Plus, minus, and multiplication appear. The expression field shows the operator the engine used.
The expression is ASCII: 14+9, 20-4, 6*7. That string is for your log and for a person checking the work. The portal almost always wants the integer in text.
You cannot pass the operator in JSON. It has to be in the picture. If a noisy minus is read as plus, expression shows the mistake and a reliable wrong answer can be reported.
Do not evaluate expression again in the client and submit your own total. You would be second-guessing the charge decision. Submit text or refresh.
Plain digit codes that contain no operator must not use math: true.
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