Paper folding
Strategy card
A fold line acts like a mirror.
- Step 1: Find each fold, in order.
- Step 2: Unfold the LAST fold first.
- Step 3: Each hole gets a mirror twin across that fold line.
- Step 4: Keep unfolding, doubling the holes each time.
Tip: Count: 1 fold makes 2 holes, 2 folds make 4.
Worked example
The paper is folded, then a hole is punched through all the layers. What does it look like opened up?
Fold right half over onto the left, then top half down onto the bottom. Then punch one hole.
- A: paper with 4 holes at row 1 column 3, row 1 column 4, row 2 column 1, row 4 column 1
- B: paper with 1 hole at row 4 column 1
- C: paper with 4 holes at row 1 column 1, row 1 column 4, row 4 column 1, row 4 column 4 (the answer)
- D: paper with 2 holes at row 1 column 1, row 4 column 1
- E: paper with 2 holes at row 4 column 1, row 4 column 4
Why: Every layer gets a hole. Unfold one step at a time: each fold line works like a mirror, so each hole gets a twin on the other side of the fold. 2 folds make 4 holes in all.
Your turn
Your turn 1 of 3
The paper is folded, then a hole is punched through all the layers. What does it look like opened up?
Fold bottom half up onto the top, then right half over onto the left. Then punch one hole.
Your turn 2 of 3
The paper is folded, then a hole is punched through all the layers. What does it look like opened up?
Fold right half over onto the left, then left half over onto the right. Then punch one hole.
Your turn 3 of 3
The paper is folded, then a hole is punched through all the layers. What does it look like opened up?
Fold top half down onto the bottom, then bottom half up onto the top. Then punch one hole.
Keep practicing
Grown-ups: Make paper snowflakes and predict the design. Parent guide
Next lesson: Rule out wrong answers