Final answer:
To find the total number of children who attended the fair on opening day, add 351 to 4000, giving a result of 4351 children.
Step-by-step explanation:
The number of children who attended the fair on opening day is calculated by adding 351 to the value of 4 thousands. To find the answer, we follow these steps:
- Identify the value of 4 thousands, which is 4000.
- Add 351 to 4000 to get the total number of children who attended the fair.
- Perform the addition: 4000 + 351 = 4351.
Therefore, 4351 children attended the fair on the opening day.