### Theory:

Decimal point position:
1. When a decimal number is multiplied by $$10$$, $$100$$, $$1000$$, $$10000$$, we move the decimal point by $$1$$, $$2$$, $$3$$ and $$4$$ places respectively to the right side of the number.

2. When a decimal number is divided by $$10$$, $$100$$, $$1000$$, $$10000$$, we move the decimal point $$1$$, $$2$$, $$3$$ and $$4$$ places respectively to the left side of the number.
Example:
1. Multiply $$125.643$$ by $$10$$.

Number of zeroes in $$10$$ is $$1$$. So, move the decimal point by one place to the right.

$$125.643 \times 10 = 1256.43$$

2. Multiply $$125.643$$ by $$100$$.

Number of zeroes in $$100$$ is $$2$$. So, move the decimal point by two places to the right.

$$125.643 \times 100 = 12564.3$$

3. Divide $$125.643$$ by $$10$$.

Number of zeroes in $$10$$ is $$1$$. So, move the decimal point by one place to the left.

$\frac{125.643}{10}$ $$= 12.5643$$

4. Divide $$125.643$$ by $$1000$$.

Number of zeroes in $$1000$$ is $$3$$. So, move the decimal point by three places to the left.

$\frac{125.643}{1000}$ $$= 0.125643$$