Question

How do you write $0.0045$ in scientific notation $?$

Answer 1

We have to know what is scientific notation. We use scientific notation to write a large expression very easily in a small way. And it is expected all over the world. So this is very convenient and easy to communicate with people from other countries. With the scientific notation the communication between scientists and students also from various countries became so easy. So this is the main reason to use scientific notation.

Complete answer:
This is a way to write very large or very small numbers. Like if we say, $450000000$, then we can write it like $4.5 \times {10^{ 8}}$. Now, by this we can express a huge number in a easy and simplest way. The proper format of scientific notation is a $x{10^{ b}}$. Where a is a decimal number which is greater than or equal to one and less than ten.

Here b is the power of ten. It can be anything depends upon the number. Now, here in this question, we have to move the decimal because there we need one non zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the ten. So, here $0.0045 = 4.5 \times {10^{ - 3}}$. Here the decimal moved to the right. So that is why the exponent becomes negative.

Note: We can get confused between positive and negative power values. But always we have to keep that in our mind that if the exponent is positive then the decimal will move to the left and if the exponent is negative then the decimal will move to the right side.