Converting a number from hexadecimal (base 16) to decimal (base 10) involves understanding the value each digit in a hexadecimal number represents and then summing up these values.
Here's a stepbystep guide:

Identify the digits in the hexadecimal number. Each digit can be a number from 0 to 9 or a letter from A to F, where A represents 10, B represents 11, C represents 12, D represents 13, E represents 14, and F represents 15 in decimal.

Starting from the rightmost digit (also known as the least significant digit), multiply it by 16 raised to the power of 0 (since 16^0 = 1, this leaves the rightmost digit unchanged).

Move one digit to the left and multiply it by 16 raised to the power of 1 (which is 16), then add this to the previous result.

Continue this process, increasing the power of 16 each time you move one digit to the left.

The final sum is the decimal equivalent of the hexadecimal number.
Let's take the hexadecimal number A3 as an example:

Identify the digits: A and 3. In decimal, A represents 10.

Starting from the rightmost digit, 3 * (16^0) = 3.

Move one digit to the left: A (which is 10 in decimal) * (16^1) = 160.

Add these values together: 3 + 160 = 163.
So, the decimal equivalent of the hexadecimal number A3 is 163.