Find the average order value with AVERAGE
Calculate the mean value of a set of customer orders.
AVERAGE
Finance runs on spreadsheets that other people rely on without checking. That raises the bar: a formula that is merely usually right is a liability, because nobody downstream will catch it.
Most finance Excel work is not modelling — it is reconciliation, variance analysis and building the same report faster than last month. The skill that separates people is not knowing exotic functions; it is building sheets that survive a new row being added, a column being inserted, or a colleague reopening them in six months.
Hard-coded ranges. A variance report built against A2:A47 quietly stops covering the data the month a 48th row appears, and because the total still looks plausible, nobody notices until someone reconciles it by hand.
Expect to be handed two tables and asked to join them, then asked what happens to your formula when a column is inserted. The answer they want involves XLOOKUP or INDEX/MATCH, and an explanation of why VLOOKUP's column number is fragile.
17 exercises using the situations above, ordered from most approachable to hardest.
Calculate the mean value of a set of customer orders.
AVERAGE
Identify the extremes in a column of values.
MAX · MIN
Divide actual sales by target to get an achievement percentage.
Count how many rows meet a numeric condition.
COUNTIF
Add up only the rows matching a text condition.
SUMIF
Combine INDEX and MATCH to look up a value without a fixed column number.
INDEX · MATCH
Apply two conditions at once to a conditional sum.
SUMIFS
Count rows that satisfy several criteria at once.
COUNTIFS
Return one of three labels depending on where a value falls.
IF
Require two conditions to be true at once.
IF · AND
Return the right rate from several tiers without nesting.
IFS
Work out how many days old each invoice is.
TODAY
Combine date arithmetic with a conditional label.
IF · TODAY
Use absolute references so a lookup does not break when copied down a column.
XLOOKUP
Combine ranking with a lookup to return a name, not just a number.
LARGE · INDEX · MATCH
Diagnose and correct a formula that returns the wrong answer.
IF
Produce a summary line combining count, total and average for one region.
COUNTIF · SUMIF