How do you convert 85 into binary?

Answer 1

To convert from any base to another:

1. Divide the number by the new base to get a quotient and a remainder.
2. Note the remainder.
3. If the quotient is zero stop as the remainder is the number in the new base.
4. Divide the quotient by the new base to get a quotient and a remainder.
5. Write the remainder in front of the previous remainder(s).
6. Repeat from step 3.

For example, to convert 8510 to octal (base 8):

85 / 8 = 10 r 5 (answer so far: 5)

10 / 8 = 1 r 2 (answer so far: 25)

1 / 8 = 0 r 1 (answer so far: 125)

quotient 0, so 8510 = 1258.

To convert 8510 to binary:

85 / 2 = 42 r 1 (answer so far: 1)

42 / 2 = 21 r 0 (answer so far: 01)

21 / 2 = 10 r 1 (answer so far: 101)

10 / 2 = 5 r 0 (answer so far: 0101)

5 / 2 = 2 r 1 (answer so far: 10101)

2 / 2 = 1 r 0 (answer so far: 010101)

1 / 2 = 0 r 1 (answer so far: 1010101)

quotient 0, so 8510 = 10101012.