The original problem-poser needs to clarify what they mean by
A = 01000001.
Obviously, a letter (unless it is a variable) does not equal a number.

HOWEVER, I think that what is implied in the question is that the CODE FOR A THAT COMPUTERS USE has the representation 01000001. This code is called ASCII (American Standard Code for Information Interchange), and it uses the values 0-255 to represent many characters. Another similar system is called Unicode, which uses 32-bit numbers to represent a wide range of international characters. I think that ASCII and Unicode agree on the first 256 characters.

So, with this idea in mind, it is true that 'A' gets the ASCII value of 65. In binary, this is written as 01000001, when the number is padded to 8 bits. Note that 'a', lowercase, has the ASCII value 97, represented as 01100001. (The capital and lowercase letters are essentially different characters with different codes.) Also, 'B' has the value of 'A' + 1, 'C' has the value of 'A' + 2, etc.
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Once you get more familiar with base conversions, you'll find there's a very easy way to find the ASCII values for many familiar characters. It uses base-16 called hexadecimal.

Essentially, the number characters (0-9) start at 30 in hex, or 48 in decimal.
The uppercase characters start just after 40 in hex, or 64 in decimal.
The lowercase characters start just after 60 in hex, or 96 in decimal.