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Open Calculator from the module Tools area. You can also open the standalone calculator at learnterms.com/tools/calculator.

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Enter a calculation

  • Type in the expression field or use the keypad.
  • Use sin, cos, tan, ln, log, square root, powers, and π as needed.
  • Switch DEG and RAD before using trigonometric functions.
  • Read the result as you type.
  • Click the result to copy it.
  • Press Enter or click = to add the result to History.
Ans inserts the newest history result into the current expression.

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Use a formula

Select Formulas, then choose one of the built-in formulas: Enter the labeled values. The displayed equation fills in and recalculates as the values change. Keep the prescription sign when a formula asks for a signed value.

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History and saved state

  • History keeps up to 30 calculations.
  • Click a history expression to reuse it.
  • Click a history result to copy it.
  • Select Clear under History to remove the list.
  • The current expression, selected formula, formula inputs, angle mode, and history stay in local browser storage.
Calculator state is browser-specific. It does not sync through your LearnTerms account.

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Why use it

  • Keep the question visible while calculating.
  • Reduce copying between LearnTerms and another app.
  • Reuse a result without retyping it.
  • Use labeled optometry formulas to reduce unit and transcription mistakes.
The calculator supports the work. You still need to choose the correct formula, units, signs, and clinical interpretation.