how mathematical operations inside computers is possible if binary numeric character codepoints value are not the same as the numeric character

Question

How if the (ascii) numeric character(0123456789) codepoints are not the same binary equivalent values of the (ascii) numeric character mathematic operations inside computer systems is done for example

the ascii value of numeric character 1 is 00110001 not 00000001 in this case how mathematical operations are possible if the binary codepoint of 1 is not 00000001