Papi Calot planned to plant 7 rows of 18 potato plants each, so the total number of potato plants he planned to plant is 7 x 18 = 126.
He still has some space left, so he wants to add 15 more potato plants.
Therefore, he needs to buy 126 + 15 = 141 potato plants.
#### 141
The answer is: 141
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
If Papi Calot planned to plant 7 rows of 18 potato plants each in his garden but still has some space left, and he is considering adding 15 more potato plants, how many potato plants does he need to buy?

### Answer:
