To express the scale of 9 centimeters = 1 meter as a scale factor, we can represent it as a ratio.
First, we note that 1 meter is equal to 100 centimeters. Therefore, we can convert the scale into centimeters:
Scale: 9 centimeters (drawing) = 100 centimeters (actual size).
Now, we can write this as a ratio:
\[ 9 \text{ cm} : 100 \text{ cm} \]
To simplify this ratio, we divide both sides by 9:
\[ 1 : \frac{100}{9} \]
Expressing \( \frac{100}{9} \) as a decimal gives approximately 11.11, but we generally keep the ratio in fractional form. Therefore, the final answer is:
\[ 1 : \frac{100}{9} \]
Alternatively, if we want to express it in a simpler integer format:
The simplified form of the ratio is:
\[ 9 : 100 \]
So the scale factor of the drawing is:
\[ \boxed{9:100} \]