How is 01000001 equal to 65?

Answer 1

It is binary, or base 2. Reading from right to left the digits represent powers of 2, starting from 1. So the 1 on the end is 1, the next 0 represents the amount of 2s, then 4s, 8s, 16s, 32s, 64s and 128s. If we lay it out like this we can see how it works:

1 x 1 = 1

0 x 2 = 0

0 x 4 = 0

0 x 8 = 0

0 x 16 = 0

0 x 32 = 0

1 x 64 = 64

0 x 128 = 0

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Total = 65