2. Round \( 43.9105 \mathrm{~km}^{2} \) to (a) 1 decimal place,

To round \( 43.9105 \text{ km}^2 \) to one decimal place, you need to look at the second decimal. Here, it's a 1. Since 1 is less than 5, we keep the first decimal (9) as it is and drop the rest. Thus, \( 43.9105 \text{ km}^2 \) rounds to \( 43.9 \text{ km}^2 \). Rounding can sometimes feel like a roundabout journey, but remember, it's all about the neighbor next door (the digit right after the one you want)! If that neighbor is 5 or above, you round up; if it's below 5, you simply wave goodbye to the digits after. Easy as pie, right?