How do you write $6.7$ in scientific notation?

Hint: First we will specify the scientific notation and then mention its format. Mention how to write the number in two ways that is in even and odd. Then we will mention all the steps required to convert a number from scientific notation.

Complete step-by-step solution:
We will start by writing numbers in scientific notation in the form $x \times {10^n}\,$ where $n$ is an integer and $x$ is in limits $[1,10)\,$ that is $1 \leqslant x \leqslant 10$. There are two methods for extracting square roots of such numbers.

Now if $n$ is even take the square root of $x$ and ${10^n}\,$ and multiply them or if we have $n$ as odd, we will multiply $x$ by $10$ and reduce $n$ by $1$ to make it even and then take square root of each and multiply them.

When we write a number in two parts: with just the digits that are with the decimal point placed after the first digit. Followed by $ \times 10$ to a power that will put the decimal point back where it should be. To convert a number from scientific notation, you move the decimal over so that you have a single digit to the left of the decimal. Count the number of decimal places you moved it, and that becomes the exponent on ten.
$6.7 = 67 \times {10^{ - 1}}$

Hence, the representation of $6.7$ in scientific notation is $67 \times {10^{ - 1}}$.

Note: For square roots evaluate the reverse of a square. The square root symbol basically means the opposite of the $2$ symbol. Be careful while taking the square root and also consider the signs of the numbers. While moving the decimal always traces back to avoid any mistakes.