Challenge 2: Diagnosing "Count of Sales" Instead of "Sum of Sales" — Solution Walkthrough

Most likely cause 1: the Sales column is stored as text, not numbers.

This is exactly the scenario this chapter's own warning box describes
— a column that LOOKS numeric (e.g. every cell displays something
like "1200") but was actually entered or imported as text is treated
by a PivotTable as non-numeric data, and defaults to Count rather
than Sum the moment it's dropped into Values.

  Fix: select the Sales column in the source data, use Data > Text to
  Columns (clicking through with the default options is often enough
  to force a genuine numeric conversion), or multiply the column by 1
  in a helper column, then refresh the PivotTable and re-drag the
  (now genuinely numeric) field into Values.

Most likely cause 2: the PivotTable's Values field setting was
manually changed to Count at some point (deliberately or by accident)
and simply hasn't been changed back.

  Fix: click the "Count of Sales" field inside the Values area,
  choose Value Field Settings, and change the aggregation back to
  Sum directly — no need to touch the source data at all if the
  underlying Sales column genuinely is numeric.

How to tell which cause applies:

Click any individual cell in the actual Sales column of the raw
source data (not the PivotTable) and check its default alignment.
Chapter 1 established that Excel right-aligns genuine numbers and
left-aligns text by default — if the Sales values are left-aligned in
the source data, cause 1 (text, not numbers) is the real problem, and
Value Field Settings alone will not fix it, since Sum still won't be
offered as a real option until the underlying data is genuinely
numeric.