2asqrt9a^3b - 3bsqrt20a^2b + 2a^2sqrt16ab

Help?!

2,965,368 round this to the nearest hundred thousand.

any suggestions?

the hundred thousanth place is the 6 in the thousanths place. the number before that is 5. so 6 changes to 7 and the rest zero. like this 2,970,000.
i hink that's it.