Question

How do you write \[0.4\% \] as decimal?

Answer 1

Hint: In the given question, we have been given a percent number. We have to then convert the percent number into its decimal form. To convert to decimal, we just count two numbers from the left and put the dot to the right of the third number or to the left of the second number. This gives us the decimal form.

Complete step-by-step answer:
The given percent number is \[0.4\% \].
To convert to decimal, we just count two numbers from the left and put the dot. But here, there is already a dot in the given number. So, we first convert the given percent number into fraction percent number.
\[0.4\% = \dfrac{4}{{10}}\% \]
So, we have to convert \[\dfrac{4}{{10}}\% \] to decimal.
To convert to decimal, we divide the number by \[100\], so we have,
\[decimal = \dfrac{{\dfrac{4}{{10}}}}{{100}}\]
Clubbing the two denominators together,
\[decimal = \dfrac{4}{{1000}}\]
Now, we count three places from the left (including the given \[4\]) and drop the decimal,
\[decimal = .004\]
Hence, \[0.4\% = 0.004\]

Note: In the given question, we had to convert a percent number to decimal. We did that by dividing the percent number by hundred. A lot of students make mistakes by not directly dividing the number by hundred; they write the given number in numerator, hundred in denominator, convert the fraction into lowest term, and then divide the obtained number. This method is very time consuming and prone to error. So, if we follow the method used above, we can solve the question very quickly and have way less chances of error.