Paper Folding & Cutting
A sheet is folded one or more times, a hole is punched, then unfolded — predict the pattern of holes. Each fold doubles the holes by reflecting them across the fold line. Work backwards: unfold the last fold first, mirroring every punch across that crease.
Each fold doubles the holes
When you punch through a folded sheet, every layer gets a hole. Unfolding mirrors each hole across the crease — so one punch through a sheet folded once gives two holes, folded twice gives four, and so on.
✅ Solved examples
✏️ Practice — try these, take hints as needed
📝 Topic test — 8 questions
Auto-graded with full solutions; saved to your dashboard. Use the calculator and formula sheet (top-right) any time.
Formula Reference Sheet
The governing rules
| Mirror image | left ↔ right (vertical mirror) |
|---|---|
| Water image | top ↔ bottom (horizontal/water surface) |
| Dice | opposite faces sum to 7 (standard die) |
| Painted cube (n×n×n) | corners 8, edges 12(n−2), faces 6(n−2)², inner (n−2)³ |
| Paper folding | each fold doubles the punched holes (2^folds) |