Year 9 Computing — Hexadecimal numbers

Read a hexadecimal number, turn it into decimal or into binary, and say why programmers write bits this way.

Name: ________________________

1.Which point on the line is the hexadecimal number 3A written in decimal?
Mark the line with an X.
2.Only one of these four is not a hexadecimal number at all. Which one?
- a) 3G4
- b) A0C
- c) 9FB
- d) 72E
3.Two hexadecimal digits are written side by side. What is the largest decimal number the pair of them can hold between them?
- a) 256
- b) 128
- c) 99
- d) 255
4.Hexadecimal needs sixteen digits, so after 9 the letters carry the count on. What is the digit C worth in decimal?
5.Match each hexadecimal digit to the four bits it stands for.
- 4
- 7
- 9
- D
- E
- 0100
- 1110
- 0111
- 1101
- 1001
6.Write the decimal number 200 in hexadecimal. Use two hexadecimal digits.
7.Write the decimal number 45 in hexadecimal. Use two hexadecimal digits.
8.A byte is eight bits long. How many hexadecimal digits does it take to write one whole byte?

Answer key — Year 9 Computing — Hexadecimal numbers