Question

How do you write $90,000,000,000$ in scientific notation?

Answer 1

Hint : We have been given a very large number and we can decipher this because of the ten zeroes given after the number nine. Thus, we shall first carefully count the number of zeroes, put the decimal point only after one digit and accordingly assign a positive or negative power to $10$ in order to write the given number in scientific notation.

Complete step-by-step solution:
The scientific notation of any figure follows certain rules. The decimal point comes after one digit only. Rest of the digits are placed after the decimal point and the zeroes are represented as $10$ raised to some negative or positive number.
We have been given the number, $90,000,000,000$. It can also be written as $90000000000.00$. On counting with precision, we get that there are a total eleven digits in the number separated by multiple commas. But we need only one significant digit before the decimal point, therefore, we must take the decimal point $10$ digits towards the left and then balance the zeroes by raising $10$ to the power of $10$, (because the decimal point was dragged ten digits towards the left).

Therefore, the scientific notation is given as $9\times {{10}^{10}}$.

Note:
In any kind of science, we deal with very large numbers like the number of atoms in our body as well as very small numbers like the mass of an atom. Such numbers which are either very large or very small also become unreadable. The possible mistake one can make is writing $-10$ instead of $10$ as the power of $10$. So, we have to be very careful while solving.