Question

How do you use place value to round off \[\$21.38\] to the nearest tenth of a dollar.

Answer 1

Hint: According to the question we have to find the round off to the nearest tenth of the given number \[\$21.38\] . So, first of all we have to find the tenth place of the given number and after finding the tenth place of the given number now we will find the hundredth place of the given number
For the rounding off to nearest tenth:
 If its digit at its hundredth place is equal to 5 for greater than 5 so, we replace the tenth digit by adding 1 and the hundredth digits by 0 and if its digit at its hundredth place is less than 5 So, we replace the digit at hundredth place digit by 0 and keep the other digits as they are.

Complete step-by-step answer:
We have given that,
 \[\Rightarrow \$21.38\]
As we can observe that,
The digit at tenth place is \[3\] and the digit at hundredth place is \[8\] .
Thus, the digit at hundredth place is greater than 5, so to round off to the nearest tenth we need to add 1 to the digit at the tenth place and replace the digit at hundredth place by 0.
Therefore,
The required number is \[\$21.40\] .
So, the correct answer is “ \[\$21.40\] ”.

Note: Students need to remember that while rounding off the number is that, Rounding of a number to nearest tenth means we approximate it and for this we do not need a number beyond tenth.
As we have in decimal number system, a number from 0 to 9 at a place,
if we have a number from 0 to 4, we remove the numbers beyond those desired completely - for example if a number is \[3.14159~\] and we need to round it to nearest hundredth, as we have 1 next to number in hundredth place, we just ignore it and write \[3.14.\]
If we have a number from 5 to 9, we remove the numbers completely, but add 1 to the last desired digit.