The nearest whole number is 1, so that could be the best number.
To the nearest whole number it is 61
9 is the best estimate whole number
which is the best approximation of
rational
JLS are the best band. They will never be forgoten. They have the best album and they have the most number of fans in the whole entire world.
Which subset of the rational numbers best describes the dimensions of a rectangle
Any time you are comparing portions of a whole, and all the portions add up to 100% of the whole, a pie chart is the best way to go.
An atom's atomic number is best described as the number of protons in its nucleus, which determines its chemical element. It is written as a whole number above the chemical symbol of an element on the periodic table.
For smaller numbers, this is best done by trial and error.
What's "best" depends on what you are going to use this for. You can take a calculator and do the exact calculation. Or you can round the numbers in a way that makes it easy to do the calculations in your head.
The best estimate for 83.74 plus 2.93 can be found by rounding each number to the nearest whole number. Rounding 83.74 to the nearest whole number gives us 84, and rounding 2.93 to the nearest whole number gives us 3. Adding these rounded numbers together gives us an estimate of 84 + 3 = 87.