Help with maths question on exponents please

[InterruptingCoww]

Hello,
How on earth do I solve this? Please help, it’s on a primary school maths comp but it is the last question so think it’s more high school level. Many thanks for any help

God - yes. “This bit is trivial so I will leave it as an exercise.” 14 hours later…..

Yes - I did the first digit and the number of digits by logs. I originally tried to approximate it by saying that 1000 is similar to 1024 but they said that wasn’t close enough…..

The last digit didn’t fell trivial to me aged 17 and terrified……

and “is left as an exercise for the reader”. My hours of doing “trivial exercises”, preparing for IMO style exams made it the worst lie of all time 😂