2014.12.20 Study Summary

December 20, 2014 afternoon

A Binary conversion

Computer base system: Binary, Decimal, octal, Hex.

(a) binary → decimal

1. Add the right to the exhibition

Step: The first step: Write "2".

The second step is to mark the index, starting from right to left 0.

The third step: multiply coefficient, each correspondence.

Fourth step: Add.

Example: Two-class system number: 11010 turn decimal.

11010

The first step

2 2 2) 2 2

Step Two

24 23 22) 21 20

Step Three

24*1 23*1 22*0 21*1 20*0

Fourth Step

24*1+23*1+22*0+21*1+20*0=26.

2, Mental Arithmetic law:8421

Example: Binary number 11010

1 1 0) 1 0

↓↓↓↓↓

8 4 2 1 is 16+8+2=26.

(b) decimal → Binary

(except for the second redundancy)

The first step: use Vertical to decimal number in order to divide 2, record each step remainder.

The second step: always in addition to the quotient 0, the remainder is recorded from the bottom up, that is, the binary number.

(c) octal → Decimal

(d) decimal → octal (045)

(v) hex → Decimal

(vi) decimal → Hex (0x12,0x234) (0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f)

(vii) binary → octal ( right-to-left three-digit group )

(eight) octal → Binary ( split three )

(ix) binary → hexadecimal (right- to-left four-digit group )

(10) hex → Binary ( split four )

2014.12.20 Study Summary