The $n$th row of Pascal's Triangle has $n+1$ numbers.
So, the first $20$ rows will have $1+2+3+\dots+20 = \frac{20 \cdot 21}{2} = \boxed{210}$ numbers.
The answer is: 210
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
How many numbers are in the first $20$ rows of Pascal's Triangle (from the $0$th row to the $19$th row)?

### Answer:
