Answer:

6

Step-by-step explanation:

[tex]log_{10} (1,000,000) \\ \\ = log_{10} (10^{6} ) \\ \\ = 6log_{10} (10) \\ \\ = 6 \times 1 \\ ( \because \: log_{10} (10) = 1) \\ \\ = 6[/tex]