How do I create consecutive numbers preceding every group that shows up in the randomizer?

Hi there, one way this can be put in place is by using JavaScript to update an HTML element to display a number that gets incremented each time the Part Number page advances.
To give it a try, first head to the Survey Flow and create an Embedded Data element at the top of the Survey Flow. Create a field called "Part" and set its value to "1", like in the below:
Next, back in the Builder, add a Text/Graphic question to the top of each of the 4 Blocks. Using the Rich Content Editor's HTML/Source view "<>", update the question text for each with the below:

Then, update the JavaScript for each of these Text/Graphic questions with the below:
Qualtrics.SurveyEngine.addOnload(function()
{
/*Place your JavaScript here to run when the page loads*/

});

Qualtrics.SurveyEngine.addOnReady(function()
{
/*Place your JavaScript here to run when the page is fully displayed*/

var partnum = parseInt("${e://Field/Part}");
document.getElementById("partnum").innerHTML=partnum;

});

Qualtrics.SurveyEngine.addOnUnload(function()
{
/*Place your JavaScript here to run when the page is unloaded*/

});

Qualtrics.SurveyEngine.addOnPageSubmit(function() {

var partnum = parseInt("${e://Field/Part}");
partnum=partnum+1;
Qualtrics.SurveyEngine.setEmbeddedData('Part', partnum);

});
When the page loads, the HTML element will display whatever the value of the Embedded Data field "Part" is. Then, when the page advances, the value of this Embedded Data field gets updated by 1.