Folding a Net into a Cube

🎯 Learning Objective

Decide which faces end up opposite (and which adjacent) when a flat net is folded into a cube.

💡 Concept

• A net is the flat pattern of 6 squares that folds up into a cube
• Skip-one rule: in a straight strip of the net, faces with exactly ONE square between them are opposite
• Faces that share an edge in the net become ADJACENT in the cube, never opposite
• A cube has exactly 3 pairs of opposite faces — fix those first, the rest are adjacent
• For the standard cross net, read the row and the column separately with the skip-one rule
• Rotating or re-folding never changes which pair is opposite

✏️ Easy Example

Q. A cross net has 1 on top, then 2, 3, 4, 5 in the middle row (left to right), and 6 at the bottom (1 and 6 lie above and below 3). Which face is opposite to 3?

1. In the middle row 2-3-4-5, skip one: 3 and 5 have exactly one square (4) between them
2. So 3 is opposite 5

Answer: 5

🇮🇳 Real-Life Example

Folding a flat mithai carton into a box, the flap sitting one gap away becomes the far side (opposite), while the flaps sharing a crease become the sides — the same skip-one logic.

📝 Exam-Level Example

Q. In the same cross net (1 top; 2, 3, 4, 5 middle row; 6 bottom), which face is opposite to 2?

1. In the row 2-3-4-5, skip one: 2 and 4 have exactly one square (3) between them
2. So 2 is opposite 4

Answer: 4

📝 Exam-Level Example

Q. In the same net, which face is opposite to 1?

1. Read the vertical column 1-3-6: 1 and 6 have exactly one square (3) between them
2. So 1 is opposite 6 (that leaves 2-4 and 3-5 as the other opposite pairs)

Answer: 6

🪄 Memory Trick

Only opposite pairs matter. In any straight line of the net, jump one square to find the partner: 1-6, 2-4, 3-5 for the standard cross net.

⚠️ Common Mistakes

• ❌ Calling two touching (edge-sharing) faces opposite — touching means adjacent
• ❌ Forgetting to check the vertical column as well as the horizontal row
• ❌ Trying to track all faces at once instead of fixing the 3 opposite pairs first

🏆 Exam Tips

• ✅ List the 3 opposite pairs first; everything not paired is adjacent
• ✅ The centre square of a cross net touches four faces — its opposite is the far end of the strip

📌 Summary

• Net folds 6 squares into a cube
• Skip-one square in a straight line → opposite faces
• Edge-sharing squares → adjacent faces
• Standard cross net pairs: 1-6, 2-4, 3-5