Round 387422 to the hundred thousand

In order to figure out the question you have to first get familiar with the places.
  hundred thousands   ten thousands   thousands  hundreds    tens     ones
               3                            8                        7               4             2            2

Now that you know what all the places are you can round.
Since it is asking for the hundred thousands place, you can look and see that there is a 3 there. In order for that number to round up to 4, the number in the ten thousands place would have to be 5 or greater. Since it is an 8, it can be rounded up. Once you round up, you have to change every number behind the hundred thousands place to 0.
It should look like this:
4  0  0  0  0  0

I hope this helped!

If you need an equation, it would be y=2x+8, y would be how long it grew, x being weeks.if you need how long he was asleep, it would be 4 weeks if he started with no beard, the equation would be x=8÷2if he did have a beard before hand, the equation would be 2w+x=8