Solve: 56+0?57-0 Finding the Missing Digit in Addition

To solve this problem, we will follow these steps:

• Step 1: Simplify $56 + 0 - 0$. Since adding or subtracting zero does not affect the number, this simplifies to $56$.
• Step 2: The expression $57 - 0$ simplifies to $57$ because subtracting zero does not change the value.
• Step 3: Now that we have $56$ and $57$, we need to determine the appropriate relational operator between these two numbers.

Comparing $56$ and $57$:
- We know that $56$ is less than $57$.

Therefore, the correct relational operator is $<$.