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?

Verified Answer :

Scryt

With rounding:
\(4\) is less than \(5\) so we round it down to whole number:
\(9.4\approx9\)

\(6\) is more than \(5\) so we round it up to whole number:
\(62.6\approx63\)

Now we have to add rounded numbers
\(63+9=72\)

Without rounding:
\(62.6+9.4\) to make it more visible I will write it differently:

\(62+9+0.6+0.4\) is equal to \(62.6+9.4\)

we can see that \(0.6+0.4\) is equal to \(1\)

so:
\(62+9+1=72\)

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 \(62.4+9.4\)  ( \(0.4\) is just an example it could be any other number between \(0-4\) ) because in this case it will be equal \(71\) and another example \(62.5+9.5\) (in this case \(0.5\) is just an example, it can be any other number between \(5-9\) :) ) and here, answer for this equation is \(73\).