784 is the answer. Every number on the left of the fullstop is is made up of 10 tenths. So, if the no is 78, you multiply by 10 ie 780. The 1st number on the right of the fullstop is the number of tenths left (4), You can write 78.4 as 78.40, which means the same thing. It is just a more precise percentage, letting you know that there are no even smaller leftovers, in the hundreds.
784 g = 1.72842 lb
784 ounces = 49 pounds
This cannot be correctly answered because you did not say what place to round it to. For example; nearest tenths, ones, hundredths, etc.
784 square feet = 72.835 square meters.
1.72842414
Three tenths.
784 miles
46 tenths
There are 6 tenths in 0.6
45 tenths
13.5 is equal to 135 tenths.
784 is a squared number because 28*28 = 784