Number representation

Question 1

How do you convert binary to denary?

Answer 1

(eg. 01101001)

• write out binary number
• annotate above the denary scale - 128, 64, 32, 16, 8, 4, 2, 1
• add together each number from the denary scale above a 1

so eg. 64 + 32 + 8 + 1 = 105

Question 2

How do you convert denary to binary?

Answer 2

(eg. 154)

• write out denary scale
• start from highest number that fits into number, so eg. 128
• add together each of the next highest numbers that fit
  eg. 128 + 16 + 8 + 4 + 2
• write 1s underneath each number that is used in denary scale
  so eg. 10011110

Question 3

How do you convert binary to hexadecimal?

Answer 3

(eg. 01001110)

• split 8 bit binary number in half
  eg. 0100 1110
• use denary scale up to 8 and add each number above a 1 for both halves
  eg. 8, 8 + 4 + 2 = 14
• put these numbers together
  eg. 8 14
• if a number is above 9, use the hex value (…9 A B C D E etc)

so eg. 8E