Estimate the total weight of two boxes that weigh 9.4 and 62.6 pounds using rounding and compatible numbers. which estimate is closer to the actual total weight? why?

With rounding:
is less than so we round it down to whole number:


is more than so we round it up to whole number:


Now we have to add rounded numbers


Without rounding:
to make it more visible I will write it differently:

is equal to 

we can see that is equal to

so:


As you see in this example those equations are equal so it doesn't matter if you take rounded numbers or not, it may be different in case like  ( is just an example it could be any other number between  ) because in this case it will be equal and another example (in this case is just an example, it can be any other number between :) ) and here, answer for this equation is .

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.