User Guide

Upper short equals key

Tap: Add the current number or expression to the calculation list, then clear the input for the next entry.

Hold: No action.

Lower long equals key

Tap: Save an edit; undo the last calculation when the input and list are empty; otherwise calculate everything in the list, save the total to history, and clear the list.

Delete key

Hold: Clear text while typing, delete selected history records, or clear the whole calculation input. Press delete again to restore recently deleted history.

After holding to clear the input, tap once to restore it. Tap again to delete only the last character.

Add, subtract, multiply, divide

Tap: Enter an operator in the input.

Hold: Set the operator used to connect the next list item and refresh the live result.

Physical keyboard

Use the main keyboard or numeric keypad for numbers, operators, decimals, and parentheses. The equals key matches the upper short equals key; Enter matches the lower total equals key; Backspace, Delete, and Clear match the delete key. Hold shortcuts work like the virtual keyboard.

Hold number 1

Open Settings and adjust the interface scale.

Hold number 2

Search calculation history with a keyword.

Hold number 3

Select or clear all history records.

Hold number 4

Switch between left-hand and right-hand modes. Left-hand mode swaps the landscape and dual-screen layout sides and mirrors the virtual keyboard.

Hold number 5

Copy selected history records to the system clipboard.

Hold number 6

When exactly one history record is selected, restore all of its calculation entries to the list with their original order, operations, and times. After editing, use the lower long equals key to calculate; the new result replaces the original record. Nothing happens if none or several are selected.

Hold number 7

Rename the current calculation book.

Hold number 8

Quickly add a note to the current calculation.

Hold 9

Instantly creates a new calculation book and switches into it automatically, no confirmation needed. You can start calculating right away.

Hold 0

Cycles through your existing calculation books. Each hold switches to the next one and wraps from the last back to the first. Nothing happens when only one book exists.

History controls

Tap a history record to select it. Double-tap to add, edit, or remove its note. Hold to copy that record.

Hold the decimal key

Open this user guide again at any time.

Left-to-right evaluation

Expressions are evaluated strictly left to right; multiplication and division are not applied first. For example 2+3×4 gives 20, not 14. Use parentheses to control the order: 2+(3×4) gives 14.

Chaining and negative numbers

Input that starts with an operator automatically continues from the previous result or the last list entry. For example, if the previous result is 5, typing -2 calculates 5-2 and typing ×2 calculates 5×2. To enter a negative number without chaining, press minus twice: typing --2 enters -2.