On the Subject of Just Numbers

(aka #1, NO NEED TO USE A STUPID CALCULATOR!)

On the module, there will be cyan-coloured buttons with a blue background.

To disarm the module, enter three digits calculated by using the simple rules below.

First Digit

Take the number of indicators and add the number of batteries together. Then take the digital root of that number. That will be your first digit.

Second Digit

Take the number of battery holders and add the number of strikes and the 1st number in the serial number. Then take the digital root of that number. That will be your second digit.

Third Digit

Take the 2 previous digits and add them together. Take the digital root of that number. That number will be the third digit.

However, if the numbers on the buttons are red, someone has reset the code. Submit 000 to solve the module.