How do you calibrate a regal digital scale?

1. Ensure that the scale is placed on a stable and flat surface.

2. Press and hold the button for a few seconds until the display shows "0.00".

3. Place a known weight, typically 100g or 200g, on the center of the platform.

4. Wait for the reading to stabilize.

5. Press the "Cal" button. The scale will display "CAL".

6. Remove the weight and press the "Cal" button again.

7. The scale will display "0.00" and the calibration process is complete.