Unit: Admin Intermediate >  Formulas & Validations > Use Formula Fields

I completed the challenge successfully using 

TODAY()  -  Account.LastActivityDate

but when I test it the field is blank:



Tested and reloaded several times.  What am I doing wrong?

I'm working on this unit: https://trailhead.salesforce.com/modules/business_process_automation/units/flow

There's a "Designing a Flow" section about halfway down where they walk you through the creation of "quick account" flow.

Flow automatically prompts user to enter name (text field) and phone (number field) to create an account.

I created the flow and then tested it.  Phone field caused issues in testing:

(1) Phone formatting is not allowed in number field.  So I couldn't enter my test phone number as 512-123-4567.  When I try this I'm told "Error: Invalid number"
(2) So I entered number as 5121234567 in flow.  This allowed me to sucessuflly create and account.
(3) I checked to see if the account was created sucessfully.  It was created but the phone number is displayed as 5,121,234,567.

How do I get phone numbers to appear properly? e.g. 512-123-4567 or (512) 123-4567

This Challenge is full of bugs and lacks instructions on how to complete it.

In the real world, the flow that passes the challenge would never work properly and would mess up a company's data. 

As reported elsewhere, the flow created can be total garbage, the challenge only checks to see if there is a VisualForce page named "Flow Page". That's it and you pass and get the points.

But the student learned nothing helpful in this instruction.

Here is where I found problems:

1) The flow I wrote creates an account and a contact, but they are not related. Nor where they validated to be new data.
2) It is impossible to use a formula to make the CloseDate equal {!$Flow.CurrentDate} + 30. Create a new Opportunity step cannot be saved with this formula.
3) It is not possible to default the stage to Prospecting in the Create An Opportunity Step. I used a PickList on the User Data Entry Screen that provides all the stages set up for the org, and Prospecting is the default. But there is nothing preventing the user from choosing a different stage and passing that stage to the Create A Record Opportunity step.
4) While the Opportunity Amount is collected at the User screen, it is never used in the challenge.
5) It never creates an Opportunity because it doesn't know what Account to associate with the Opportunity.
6) Worst of all, the whole flow setup is written to require Adobe Flash Player. Innovative for 1995.

Would someone at Salesforce please have an experienced trainer/developer go through this module and fix everything that is wrong with it.

What was supposed to take 20 minutes took me over two hours to finish.

P.S. In a real workflow, there would be a step that checks to see if the Account or the Contact was an existing record and create a new Opportunity in the existing account and leave the contact alone and not create a duplicate.