1. The problem is to understand the value of the variable $a$ given as $a=4$. 2. This is a simple assignment where the variable $a$ is defined to be equal to 4. 3. There are no further calculations or operations needed since the value is directly given. 4. In algebra, variables can be assigned values to be used in expressions or equations. 5. Here, $a$ is assigned the constant value 4, which can be used in any subsequent calculations or formulas.