Understanding the evaluation of postfix expressions

The postfix notation, its structure, and evaluation may seem strange and difficult to grasp initially. This is because we, as humans, are used to the infix notation. However, computers can easily understand these expressions as evaluating them only requires traversal from left to right, no back-and-forth jumping, and complex precedence rules.

Consider we are given the postfix notation of a mathematical expression as a string given below, where every operand is a single-digit number.