Final answer:
The unit rate for turtle hatchlings emerging from the nest is calculated by dividing the total number of hatchlings by the total number of hours observed.
Step-by-step explanation:
The unit rate for turtle hatchlings emerging from the nest is the average number of hatchlings that appear per hour. To calculate this rate, Manny would divide the total number of hatchlings he has counted by the total number of hours he observed. For instance, if he counted 120 hatchlings over a period of 4 hours, the unit rate would be 120 hatchlings divided by 4 hours, which equals 30 hatchlings per hour.