24 is the least common denominator
45.3297 rounded to the nearest tenth is 45.3
3 is in the tenths place, so you look at the number to the right of it. If that number is 5 or more, you round up. If the number is 4 or less, you round down. So you round 45.3297 down to 45.3
Logically if you double weight on something it means that you are adding the exact same weight as the first object to the same thing to make it twice the weight as the original, so yes... the weight will double if the length is doubled
The basic idea is that multiplying by 10 just moves the decimal point one place to the right. It makes the number bigger.
4.8 x 10 = 48
4.8 x 10 x 10 = 48 x 10 = 480
Each time you multiply by another 10, the decimal point moves one more time.
The expression 
says you're going to multiply by 10 five times in a row. So that will move the decimal point 5 places to the right.
So what do you get if you move the decimal in 4.8 five places to the right?
