31 is converted to bin 011001, and then converted to decimal:
bin 011001 = (0x25) + (1x24) + (1x23) + (0x22) + (0x21) + (1x20) = dec 25
Or you can convert octal straight to decimal:
oct 31 = (3x81) + (1x80) = dec 25
So oct 31 is equal to dec 25, get it? Octal 31 has the same value as decimal 25. Both octal and October are abbreviated as oct and both December and decimal are abbreviated as dec. <