To find the area of a rectangle, you can use the formula:
\[ \text{Area} = \text{length} \times \text{width} \]
In this case, the length is 42 centimeters and the width is 18 centimeters.
First, calculate the area in square centimeters:
\[ \text{Area} = 42 , \text{cm} \times 18 , \text{cm} = 756 , \text{cm}^2 \]
Next, to convert square centimeters to square meters, you use the conversion factor that \(1 , \text{m} = 100 , \text{cm}\). Therefore, \(1 , \text{m}^2 = (100 , \text{cm})^2 = 10,000 , \text{cm}^2\).
Now, convert the area from square centimeters to square meters:
\[ \text{Area in square meters} = \frac{756 , \text{cm}^2}{10,000 , \text{cm}^2/\text{m}^2} = 0.0756 , \text{m}^2 \]
Thus, the area of the rectangle is
\[ \boxed{0.0756} \text{ square meters.} \]