✔ A cube has six square faces. The cross shape allows all sides to fold up without gaps or overlaps.
Q2. Siti buys cardboard for a box at the MRT station. If two large faces cost $2 each and four small faces cost $1 each, what is the total cost?
✔ Using the bar model: (2 x $2) + (4 x $1) = $4 + $4 = $8.00 total cost for the net.
Q3. Wei Ming chooses a net where two opposite faces touch. What is the mistake?
✔ If opposite faces touch in the net, they cannot form a closed solid when folded. They must be separated.
Show transcript
[Slide 1] Visualising Nets and Solids
Hello class, welcome to our nets lesson. Mei Ling is packing gifts at Tampines Mall. Visualise how flat paper folds into a solid.
[Slide 2] Identifying Correct Nets
Ravi reminds us to count faces carefully. A cuboid has six rectangular faces total. Check which edges join together when folded up.
[Slide 3] Calculating Cost with Nets
Siti needs a cuboid box costing ten dollars and fifty cents. The bar model shows two large faces cost more than four small ones. This helps match the correct net layout.
[Slide 4] Avoiding Overlapping Faces
Wei Ming often picks nets with overlapping sides. Remember, opposite faces must not touch in the net. Always check the folding path carefully.
[Slide 5] PSLE Revision Summary
Let us recap at the hawker centre. Count faces, visualise folding, and avoid overlaps. You are ready for the PSLE now.