Let’s work through this step by step.
We are told that a
scale drawing is made using a
ratio:
> size of scale drawing : size of original object
In the image, we see:
- The “scale drawing” (small robot) has a height labeled as
1 unit.
- The “original object” (big robot) has a height labeled as
2 units.
- So the ratio is written as
1:2.
That means:
For every
1 unit in the drawing, the real object is
2 units tall.
This also tells us the drawing is
half the size of the original — because 1 is half of 2.
So if someone asked:
> “If the original robot is 10 cm tall, how tall is the scale drawing?”
You’d do:
10 ÷ 2 = 5 cm → because the drawing is half the size.
Or if the drawing is 3 cm tall, then the original is:
3 × 2 = 6 cm.
The key idea:
→ Multiply the drawing size by 2 to get the original.
→ Divide the original size by 2 to get the drawing.
And the ratio 1:2 always means:
Drawing : Original = 1 : 2
Final Answer:
Scale Ratio 1:2 means the scale drawing is half the size of the original object. For any measurement, multiply the drawing size by 2 to get the original, or divide the original by 2 to get the drawing.
Parent Tip: Review the logic above to help your child master the concept of drawing to scale worksheet.
