From the archive
Day 11
Friday, 14 August 2026
Intermediate
Total what a customer still owes, and what's overdue
SUM answers one number. SUMIFS answers "sum this, but only where these conditions hold."
Task:
You handle accounts receivable for a small design studio. Eight invoices sit in front of you, each with a customer, a status and how many days overdue it is. In E10, total how much Bramwell Foods currently still owes — their open invoices only. In E11, total the amount of every open invoice that is more than 30 days overdue, across all customers.
The daily challenge is part of Pro
A new exercise every morning, plus every day that came before it — a back catalogue that grows by one a day, whether or not you were here for it.
Recent days
The last 14 days. Today's challenge is free while your streak is alive; Pro opens every past day too.
- 29Day 29 · Tuesday, 1 September 2026Turn three weighted criteria into one vendor scoreLatest
- Day 28 · Monday, 31 August 2026Work out take-home pay without repeating the gross pay three times
- Day 27 · Sunday, 30 August 2026Work out how many cartons an order needs, and what's left in the last one
- Day 26 · Saturday, 29 August 2026Average response time for one priority, one team
- Day 25 · Friday, 28 August 2026Set contract review deadlines from a rush flag
- Day 24 · Thursday, 27 August 2026Back into the interest rate a financing offer never quotes
- Day 23 · Wednesday, 26 August 2026Look up carrier rates without an error for the one that isn't contracted
- Day 22 · Tuesday, 25 August 2026Split an order number into its channel and sequence
- Day 21 · Monday, 24 August 2026Total a purchase order without a helper column
- Day 20 · Sunday, 23 August 2026Pull the items that need reordering off a warehouse count
- Day 19 · Saturday, 22 August 2026Rank a sales contest without reordering the table
- Day 18 · Friday, 21 August 2026Decide which support tickets get escalated
- Day 17 · Thursday, 20 August 2026Work out shipping cost from a weight bracket table
- Day 16 · Wednesday, 19 August 2026Check whether a retirement savings plan hits its target