1. Support integer and decimal operations;
2. Only support + - × ÷ operations;
3. Click the "⬅" key to delete a character. After all characters are deleted, an input line can be deleted;
4. Long press the "⬅" key to clear all input data;
5. Long press the text box to copy the selected data to the clipboard, and then copy it to other applications;
6. Click the "CY" key to copy all calculated data to the clipboard, and you can copy the data to other applications;
7. Click the "⏎" key to insert an input line, restart a calculation or increase a value;
8. Long press the "=" key to complete the recalculation of all data;
9. Click to select the text box and modify the input number;