The donation amount labels on the winter gift drive charity table have been mixed up. Every label showing tens and ones has been swapped with a different number — and each swap was chosen deliberately to look almost correct. Whoever rearranged them understood place value well enough to make every change plausible to a quick glance. They know what a tens digit means. They know how skip counting produces a sequence. They know expanded form well enough to reverse it convincingly. Five suspects. Five stations. One thief.

The Math Whodunnit: The Mixed-Up Gift Labels is Case WK-01 in the DeskMade Math Whodunnit Winter Grades K-2 series. Students work through five investigation stations — tens and ones, comparing two-digit numbers, skip counting, expanded form, and a place value synthesis challenge — decoding a code letter at each station. All five letters collected in order spell the verdict word POLAR. Wrong answers cannot spell the verdict: the built-in decoder self-corrects without any teacher involvement. A nonsense word means there is a step to check before moving forward.

This is a complete 15-page case file: eight student pages, a seven-page teacher answer key, and a ten-slide Google Slides deck. Print it and leave it on desks. Project the slides and run it whole-class. Assign it in Google Classroom. Zero prep on the day.

WHAT’S INCLUDED
8-page student worksheet PDF — print and digital ready, black and white friendly
7-page teacher answer key PDF — master verdict, station-by-station answers, debrief notes, 4 discussion questions, and extension suggestions
Google Slides deck (10 slides) — cover, mission brief, suspects board, how the decoder works, one slide per station, and final verdict reveal
Self-checking decoder mechanic across all five stations — students discover and fix their own errors without teacher input
Final Verdict page — letter boxes, suspect pill buttons, written reflection prompt
Detective’s Reflection — written-response prompts to extend thinking after the investigation