Type the sum where you're already writing and put a _ where the answer goes: 6 * 9 = _ resolves to 54, 144 / 12 = _ to 12, 5 miles in km = _ to 8.05. No calculator app, no tab switch; the answer lands in the sentence you were typing.
The shapes that work
These are drawn from the project's own benchmark suite, so each shape is tested, not hoped for:
| Kind | You type | You get |
|---|---|---|
| Arithmetic | 8 + 5 = _ | 13 |
| Worded math | seven times eight = _ · half of 50 = _ | 56 · 25 |
| Unit conversion | 70 kg in pounds = _ · 12 inches in cm = _ | 154 · 30.48 |
| Temperature | 100 celsius in fahrenheit = _ | 212 |
| Number systems | 2024 in roman numerals is _ | MMXXIV |
| Dev lookups | http status for not found _ · red in hex is _ | 404 · #FF0000 |
Your text is preserved
The fluid blank fills only the slot you left: the _ becomes the answer and every word you typed stays put, so the total is _ becomes the total is 42. If the model can't resolve it, the _ simply stays: no error state, nothing to dismiss.
How much to trust it
Honest framing: this is an LLM answering, not a calculator executing. The math and conversion categories are part of the 137-case suite the project benchmarks on, where the default provider scores 100%, so everyday arithmetic and conversions are reliable in practice. For financial-grade precision or long-decimal work, verify independently; that's true of any LLM-backed tool, and OpenCues' cycling (Ctrl+Alt+↑/↓ on the answer) lets you check alternatives or restore what you typed.
Everywhere you type
The same shapes work in every supported host: browser fields via the Chrome extension, the prompt boxes of Claude Code, OpenCode, and Gemini CLI, and your terminal via oc-shell. Plain <input> and <textarea> fields on any site get this too.
Related: What is a blank? · Context-aware lookups · 50 things to type with a blank · GitHub repo