### Theory:

We have learned how to convert numerical expression into a tree diagram.

Now, we shall learn how to convert the tree diagram into numerical expression.
Example:
Convert the given tree diagram into numerical expression.

Solution:

To find the numerical expression for the given tree diagram, let us start from the bottom of the tree diagram.

Let us subtract $$3$$ from $$4$$, we get:

$$4 - 3$$ $$= 1$$

When we multiply $$2$$ and $$1$$, we get $$2$$.

Now, we shall write the expression without changing the value.

The expression can be written as $$2 \times (4 - 3)$$.