To find the ratio of sandwiches to chicken wings, we take the number of sandwiches and divide it by the number of chicken wings.
Maria is making 40 sandwiches and 25 chicken wings.
The ratio is given by:
\[ \text{Ratio} = \frac{\text{Number of sandwiches}}{\text{Number of chicken wings}} = \frac{40}{25} \]
To simplify this fraction, we can divide both the numerator and the denominator by their greatest common divisor, which is 5:
\[ \frac{40 \div 5}{25 \div 5} = \frac{8}{5} \]
Therefore, the ratio of sandwiches to chicken wings is \( 8:5 \).