Estimate 13.87 - 6.541 by first rounding each number to the nearest tenth.
To estimate the value of \(13.87 - 6.541\), we follow a two-step process. First, we round each number to the nearest tenth according to the standard rounding rule: if the digit in the hundredths place is 5 or greater, round the tenths digit up by 1; if it is less than 5, keep the tenths digit as it is. Then, we perform the subtraction with these rounded values.
For the first number, \(13.87\), the tenths digit is 8 and the hundredths digit is 7. Since 7 is greater than or equal to 5, we round the tenths digit up from 8 to 9. Thus, \(13.87\) rounds to \(13.9\).
For the second number, \(6.541\), the tenths digit is 5 and the hundredths digit is 4. Since 4 is less than 5, we keep the tenths digit as 5. Thus, \(6.541\) rounds to \(6.5\).
Now we subtract the rounded values:
\[13.9 - 6.5 = 7.4\]
The estimated value of the original expression is 7.4.
Rounding is a fundamental skill used in everyday life to quickly estimate quantities. For instance, when grocery shopping, if you have a budget of \(\$50\) and items cost \(\$13.87\) and \(\$6.54\), you can quickly estimate their difference or total cost by rounding to the nearest tenth or dollar to keep a running tally in your head without needing a calculator. This ensures you stay within your budget while shopping efficiently.