To make the calculation as small as possible using the six cards (1, 2, 3, 5, 7, 9), the goal is to create two three-digit numbers with the smallest possible sum. To achieve this:

1. Arrange the smallest digits in the hundreds, tens, and units places for both numbers.
2. Distribute the smallest numbers evenly.

Solution:

• Use the digits 1, 2, and 3 for one number, forming 123.
• Use the digits 5, 7, and 9 for the second number, forming 579.

Thus, the calculation becomes:

$123 + 579 = 702$

Final Answer:

The smallest possible result of the calculation is 702.

Would you like further clarification or details? Here are 5 related questions:

1. Why does placing the smallest digits first reduce the sum?
2. Can we use other combinations to verify this solution?
3. How would the solution change if subtraction was required instead of addition?
4. What is the largest possible result from the given numbers?
5. Can this method apply to problems with more digits?

Tip: Always arrange numbers strategically by place value (smallest to largest for minimizing results, largest to smallest for maximizing).