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.
 
1220_6.svg
 
Solution:
 
To find the numerical expression for the given tree diagram, let us start from the bottom of the tree diagram.
 
1220_7.svg
 
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 \(2 \times (4 - 3)\).