In mathematics, estimation means approximating a quantity to the required accuracy. This is obtained by rounding off the numbers involved in the calculation and getting a quick and rough answer.
To approximate numbers,
We can give the following examples
Example 1
[tex]8.9\times2.1[/tex]We can approximate the numbers as follow
[tex]\begin{gathered} \text{For 8.9} \\ we\text{ will round 9 up to give 1} \\ \text{This is then added to 8 to give 9} \\ \text{Thus} \\ 8.9\cong9 \end{gathered}[/tex]Similarly,
[tex]\begin{gathered} 2.1 \\ we\text{ will round down 1 to 0} \\ So\text{ that 2.1}\cong2 \end{gathered}[/tex]Thus, we will have
[tex]8.9\times2.1\cong9\times2=18[/tex]Therefore, the approximated value is 18
The actual answer is
[tex]8.9\times2.1=18.69[/tex]We can look at another example
[tex]11.23\times36.06[/tex]Thus
[tex]\begin{gathered} 11\times36=396 \\ \end{gathered}[/tex]The actual answer is
[tex]11.23\times36.06=404.95[/tex]In both cases, we can see that the approximated values and the actual values are not so far from each other.
