Excel Data Validation & Error-Proof Templates

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Turn three Data Validation rules (whole number, decimal, date range) into TRUE/FALSE check formulas for Larkspur Supply's order lines and count the failed checks.
• Check every order's region and payment terms against the allowed lists, the way a drop-down list rule does, and count the bad and the clean orders.
• Check that every order line's item belongs to its category – the logic of a dependent (cascading) drop-down – and build the INDEX/MATCH pieces of its list source.
• Check new customer records before they go into Larkspur's system: ID pattern, email shape and name length – and count the records that are ready to import.
• Build the rules that stop Larkspur from paying a supplier invoice twice: a count per invoice number, a supplier + number key, and an entry rule that blocks only the repeat.
• Validate Larkspur's project budget template where one cell depends on another: end date after start date, and the cost shares of three departments adding up to exactly 100%.
• Finish Larkspur's expense-claim form: two rule checks (one looks up the category limit), an error count for the form, and red highlighting for every invalid field.
• Measure how complete the submitted order forms are, chart it for the sales manager and track the protection checklist that makes the template ready to roll out.