Hi, I'm really confused about two's complement and octal. 1.) In two's complement, how can using the opposite and adding one change a number into the negative? 2.) If octal 7 is 111 in binary, what is 8 and 9? I have some sample problems and I'll show you my answers for some of them. Please let me know if I'm on the right track or not. Thanks! a.) Decimal: 37 Binary: 100101 Octal: 45 Hex: 25 b.) Decimal: -8 Binary: 1000 Octal: 1 Hex: 8 c.) Decimal: 10 Binary: 1010 Octal: 12 Hex: A d.) Decimal: -53 Binary: 001011 Octal: 13 Hex: B Thank you again for your help! Lene - Users can unsubscribe from this list by sending email to 24hoursupport-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field OR by logging into the Web interface at http://web.tampabay.rr.com/spider1/24hrsupport.htm.