Question

Express the following number in standard form: $ 39087.8 $

Answer 1

Hint: To express any number in standard form means you have to represent the given number in form of exponent of 10. In this standard form there is only one digit in integer form and the remaining non-zero number in decimal form.

Complete step-by-step answer:
The number is $ 39087.8 $
First take the decimal after one digit of the given digit and place the multiple of 10 in the denominator which is equal to the number converted to decimal from integer.
$\Rightarrow$ $ \dfrac{{3.90878}}{{10000}} $
So here we take four times multiple of 10 as we take four values of in decimal form from integer and last digit 8 is already in decimal form so it will be written the same.
Now, further solving the expression we get,
$\Rightarrow$ $ \dfrac{{3.90878}}{{{{10}^4}}} $
After expressing the multiple of 10 in the form of exponent, take the denominator in numerator by taking the exponent negative.
$\Rightarrow$ $ 3.90878 \times {10^{ - 4}} $
Hence, this is the standard form of the given number.

So, the correct answer is “Option C”.

Note: In this type of problem of the conversion of usual form into standard form, we have to make sure that there should only be one integral value and remaining will be decimal. When the values which are converted from integer to decimal, then the number of these values will be taken as inverse power or exponent of 10 which is in multiple with the given value. There are two types of problems in the first one: expressing the integer value in standard form. In the second one, express the decimal value in standard form. When the value is given in integer form then first convert it in decimal form and then to standard from.