In each of the following pairs of numbers, state which whole number is on the left of the other number on the number line. Also write them with the appropriate sign `(gt, lt)` between them.
530, 503

Answer

To solve the problem, we need to determine which of the two whole numbers, 530 and 503, is smaller and which is larger. We will also express this relationship using the appropriate sign (greater than or less than).

### Step-by-step Solution:

1. **Identify the Numbers**: We have two numbers: 530 and 503.

2. **Compare the Numbers**:
- We need to see which number is larger.
- 530 is greater than 503 because when we compare the digits from left to right, 5 (in 530) is equal to 5 (in 503), but the next digit in 530 is 3, while in 503 it is 0. Therefore, 530 is greater.

3. **Determine the Position on the Number Line**:
- On a number line, the smaller number is always to the left of the larger number.
- Since 503 is smaller than 530, it will be positioned to the left of 530.

4. **Write the Relationship**:
- We can express the relationship between the two numbers using the appropriate sign.
- Since 503 is less than 530, we can write:
\[ 503 < 530 \]

### Final Answer:
503 is on the left of 530 on the number line, and we can write:
\[ 503 < 530 \]