"The clubhouse model needs its own plan," Rocket says. "Bigger. Every detail."
"Then redraw the model spot at 1 cm to 25 cm," Raven says. "What do you notice about the new lengths?"
Rocket checks the old plan. "The spot was 1.5 cm at 1 to 50. That is 75 real centimeters. At 1 to 25, three centimeters."
"Doubled," Raven says. "Half the scale number, twice the drawing."
Nova hovers over both plans, her light jumping from one to the other. "Always go back to the real length first," she says.
"Next week we leave the floor and build the roof," Rocket says, reaching for the straws.
Nova hums. "Three straws do not always make a triangle."
Rocket stops. "They don't?"
| Part | At 1 cm to 50 cm | Real (cm) | At 1 cm to 25 cm | At 1 cm to 100 cm |
|---|---|---|---|---|
| Long wall | 8 | 400 | 16 | 4 |
| Garage door | 4.8 | 240 | 9.6 | 2.4 |
| Blueprint Table | 3 | 150 | 6 | 1.5 |
| Model spot | 1.5 | 75 | 3 | 0.75 |
Halving the scale number doubles every drawn length. Doubling the scale number halves them.
The real lengths never change. Only the page changes, so the real column is the bridge between two plans.
A floor plan, a map, a model car and a diagram in a build guide are all scale drawings.
Each one keeps the shapes and shrinks or grows every length by one factor. Find the scale and you can measure anything on it.
| Week review | True or false? |
|---|---|
| 1.5 × 50 = 75 | ? |
| 75 ÷ 25 = 3 | ? |
| Halving the scale number doubles every drawn length. | ? |
| Redrawing at a new scale changes the real lengths. | ? |
| At 1 cm to 20 cm, a real area is 400 times the drawn area. | ? |
A week of two lengths for everything. Tomorrow is Build Day: your family draws a room to scale.