Scientific Skills — computed, not guessed

Computed, never guessed.

A language model predicts the next word, which makes it unreliable at arithmetic, unit algebra and physical constants: it produces numbers that look right. These run in your browser, do the actual calculation, and show every step — so an answer is correct or absent. No key, no network, no account.

Where the numbers come from

SI, 9th edition (2019)

Every unit factor. SI-to-imperial conversions are exact by definition — an inch is 25.4 mm.

CODATA 2018

Physical constants, marked exact or measured. The 2019 redefinition made several exact by definition and the skill says which.

IUPAC 2021

Standard atomic weights across 94 elements, with the per-element mass fraction shown.

Shown, not asserted

If a formula was parsed wrongly you can see it in the steps, rather than discovering it later in a quotation.