To find the value of \( j \) that makes the equation \( j + 571 = 571 \) true, we can use the properties of addition.
We want to isolate \( j \). We can do this by subtracting \( 571 \) from both sides of the equation:
\[ j + 571 - 571 = 571 - 571 \]
This simplifies to:
\[ j = 0 \]
Thus, the value of \( j \) that makes the addition sentence true is \( \boxed{0} \).