Final answer:
After adding the morning feeding of 103 fish to the evening feeding of 803 fish, the estimated total number of fish the dolphins ate is 906 fish.
Step-by-step explanation:
The question requires the estimate of the total number of fish the dolphins ate given that they were fed 103 fish at 9:00 a.m. and then fed 803 more at 5:00 p.m.
To solve this, we simply add the two amounts together: 103 fish from the morning feeding plus 803 fish from the evening feeding equals 906 fish in total.
This method of adding the numbers together gives us our estimation without needing to factor in any additional considerations such as fish size, dolphins' appetite at different times, or other feeding times.