To model the total amount of water \( w \) that Martina used in her science project where she put 8.5 ounces of water into each of 5 containers, you would multiply the amount of water in each container by the number of containers.
The equation can be written as:
\[ w = 8.5 \times 5 \]
So the complete equation is:
\[ w = 8.5 \times 5 \]
This implies that the total amount of water \( w \) is the product of the amount in each container (8.5 ounces) and the number of containers (5).