Conversion Accuracy 0 / 16
Memory Rank Half-Byte
1 [2 Marks]
Convert the following 8-bit binary numbers into Denary.
(a) 0001 0101 [1]
💡16 + 4 + 1
(b) 1000 0011 [1]
💡128 + 2 + 1
✅ Mark Scheme

(a) 21

(b) 131

Score yourself (Max 2):
2 [2 Marks]
Convert the Denary number 170 into an 8-bit Binary number.
💡Use the table: 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1
✅ Mark Scheme

Answer: 1010 1010

(Working: 128 + 32 + 8 + 2 = 170)

Score yourself (Max 2):
3 [4 Marks Total]
(a) Convert Binary 1110 0110 into Hexadecimal. [1]
(b) Convert Hexadecimal 2B into Binary. [1]
(c) Explain why computer scientists use Hexadecimal to represent binary numbers. [2]
✅ Mark Scheme

(a) E6

(b) 0010 1011

(c) Reason:

  • Easier for humans to read/write/remember (1).
  • Less chance of making errors (1).
⚠️ Common Mistake Do NOT say "It takes up less storage space". Hex is just a representation for humans; the computer stores everything as binary.
Score yourself (Max 4):
4 [2 Marks]
Convert Hexadecimal 3E into Denary.
💡(3 * 16) + (14 * 1)
✅ Mark Scheme

Answer: 62

(Working: 3x16 = 48. E = 14. 48 + 14 = 62)

Score yourself (Max 2):
5 [2 Marks]
Convert Denary 214 into Hexadecimal.
💡Hint: Turn into Binary first, then split into nibbles.
✅ Mark Scheme

Answer: D6

(Working: 214 -> 1101 0110 -> D 6)

Score yourself (Max 2):
6 [4 Marks Total]
A student has the 4-bit binary number 1111.
(a) State the Denary value. [1] (b) State the Hexadecimal value. [1] (c) Identify the result of adding 0001 to 1111.
Give your answer in 4-bit binary. [2]
✅ Mark Scheme

(a) Denary: 15

(b) Hex: F

(c) Addition:

  • 0000 (1)
  • Overflow error / carry out (1)
⚠️ Common Mistake The result is 10000, but in a 4-bit system, the '1' is lost (overflow), leaving 0000.
Score yourself (Max 4):