The underlined digit is missing. So, the underlined digit is 8.
Answer:
3.900
Explanation:
Given:
The decimal number to round off is given as:
3.871
The underlined digit is 8. So, we need to round the given decimal number to nearest tenth of a decimal as the digit 8 is in the tenth place.
Now, the number next to 8 is 7 which is greater than 5.
Now, as per rounding rules, if the digit after the digit which has to be rounded off is greater than or equal to 5, then we add 1 to the underlined digit and replace all the digits after the underlined digit by 0.
So, the decimal number 3.871 becomes 3.900 on rounding it to the nearest tenth of a decimal.