Answer:
1006009
Explanation:
[tex](1003)^2 = (1000 + 3)^{2} \\ \\ = (1000)^{2} + 2 \times 1000 \times 3 + {(3)}^{2} \\ \\ = 1000000 + 6000 + 9 \\ \\ (1003)^2 = 1006009[/tex]