9:00 P.M. · THE GRAND FOYER
A stopped grandfather clock
- Rookie
- Add a decimal number of hours to a start time
5.MD.A.1 - Detective
- A clock that loses minutes every hour
6.RP.A.3 - Inspector
- A clock that runs a few percent slow
7.RP.A.3
Halloween math mystery · Grades 5 to 8
Someone stole the Midnight Lantern. Your students have until midnight.
Hollow House is a math mystery in real 3D. Students search a haunted house, open each locked clue with a math answer, cross suspects off an evidence board, and name the thief. Every student gets a different thief and different numbers, so the only way to the end is to do the math.
No student logins
Chromebooks, laptops and iPads
30 to 40 minutes
Four rooms, four locks
Each clue is locked. Only a math answer opens it.
Pick one of three levels on your teacher page and the whole class plays at that level. The story clock moves only when a student solves a room, and nothing is timed.
9:45 P.M. · THE WITCH'S KITCHEN
Vesper Hex's cauldron
- Rookie
- A fraction of a batch measured in mixed numbers
5.NF.B.45.NF.B.6 - Detective
- How many fraction-cup scoops make the recipe
6.NS.A.1 - Inspector
- Scale a recipe ratio
7.RP.A.2
10:30 P.M. · THE WRAPPING ROOM
Auntie Bones's box of bones
- Rookie
- Find the layers from the volume, or from bags of bones
5.MD.C.5 - Detective
- Surface area of a box
6.G.A.4 - Inspector
- A corner-to-corner pole or a missing side, with the Pythagorean theorem
8.G.B.7
11:15 P.M. · THE ATTIC
Gus the ghost's floorboards
- Rookie
- Move a point right, up, and back left
5.G.A.2 - Detective
- Reflect a point across an axis
6.NS.C.6.b - Inspector
- Rotate a point 90° or 180° around the origin
8.G.A.3
11:59 P.M. · The Ballroom
Four clues add up to one accusation.
Each opened lock gives a piece of evidence, and students cross off every suspect it rules out. At midnight all six suspects line up. A wrong accusation gets an alibi and a pointer back to the clue that was misread, so students try again instead of guessing their way through.
- Six suspects, six endings. The thief changes every game, so early finishers can replay for a new one.
- Real deduction at Inspector. The evidence states facts without saying who they rule out, and a guest book of sign-out times is read against the time the student set on the clock.
- A Detective Rating at the end, built from first-try answers, careful board filings, hints used and the accusation.
When a student is stuck
Help that doesn't hand over the answer.
A wrong answer never produces a wrong clue. Inkwell, the student's black-cat partner, steps in instead.
- First miss: a hint aimed at the likely mistake, like reading a decimal as minutes.
- Second miss: the first step of the problem.
- Third miss: a similar problem worked start to finish with different numbers, then a fresh problem to try.
For the teacher
One link to share. The answer key is built in.
On TPT you download a three-page Teacher Guide with a Launch button. That opens your teacher page, and that is the whole setup.
- Pick a level and share the student link in Google Classroom or any LMS, or project its QR code.
- Check any student's work from a case code. Each one-page case file prints a code; type it in and see that game's thief, problems and answers.
- An optional Detective Report: two short written answers with a live word count, copy and paste turned off.
- Simple graphics for older computers: illustrated rooms, same game.
Questions teachers ask
Before you assign it
How long does it take?
Most students finish in 30 to 40 minutes. Nothing is timed. Early finishers can replay for a new thief.
What devices does it run on?
A current Chrome, Edge or Safari on Chromebooks, laptops and iPads. The game lowers its own graphics on a slow machine, and the Simple graphics switch is there for very old ones.
Do students need accounts?
No. Students type a first name and play. There are no logins, no email addresses and no tracking, and nothing a student types leaves their device.
What if a student closes the tab?
Progress saves in the browser. Opening the link again on the same device puts the student back in the same room.
Will it load on my school network?
The game loads nothing from any other site. Play the free room on a student device first. If it is blocked, ask your tech team to allow thesimulationlabedu.com.
Is it too scary for younger students?
The suspects are cartoon monsters at a party, the rooms are candlelit, and there is no gore. Sound is on by default and one button turns it off.
Try it on a student device
Open the first lock yourself.
Room 1 is free to play right now, no sign-up. If the house loads and the clock opens, your school's devices are ready for the full case.