A number becomes 9 ones and 18 tenths when it is rounded off to 1 decimal place. What is the greatest possible value of original number?

10.847 why not 10.84999999999 ?

To find the greatest possible value of the original number, we need to understand how rounding works. Rounding to 1 decimal place means we keep 1 digit after the decimal point and remove any remaining digits.

In this case, the number becomes 9 ones and 18 tenths when rounded to 1 decimal place. This means the original number must have been between 9.05 and 9.15.

To find the greatest possible value, we can use the upper bound of 9.15. However, we must keep in mind that rounding depends on the next digit after the desired decimal place. If the digit is 5 or greater, we round up; if it is less than 5, we round down.

In this case, we know that the next digit after the tenths place is 5 (9.15), which is greater than 5. Therefore, we round up to the nearest tenth. The greatest possible value of the original number is then 9.2.