When multiplying numbers with the same base, you can simply add the exponents. So, for your expression:

$10^3 \times 10^3 = 10^{3+3} = 10^6$

Thus, the result is $10^6$, which is equal to 1,000,000.

Would you like further details on exponent rules? Let me know if you have any questions!

Here are 5 related questions:

1. How do you divide numbers with the same base?
2. What is the power rule for raising a power to another power?
3. How do negative exponents work?
4. What is the scientific notation for $10^6$?
5. How do you express large numbers in terms of powers of 10?

Tip: Always remember the basic exponent rule: $a^m \times a^n = a^{m+n}$. This is key to simplifying many expressions.