Lesson 1 - Exam practice
Test your knowledge
Work through these questions as you would in an exam. Answer the MCQ first, then write your answers to the written questions before revealing the mark scheme.
Section 1: Multiple choice
Select one answer per question. Instant feedback appears when you choose.
Question 1 of 5
Which base does the hexadecimal number system use?
Hexadecimal is base 16. It uses digits 0-9 then letters A-F to represent values 10-15. Base 2 is binary, base 8 is octal, base 10 is denary.
Question 2 of 5
What is the denary value of the binary number 10110100?
Place values active: 128+32+16+4 = 180. Always add only the positions with a 1 bit.
Question 3 of 5
A programmer uses the hex value FF. What is its denary equivalent?
F = 15. FF = (15 × 16) + 15 = 240 + 15 = 255. This is the maximum value storable in one byte.
Question 4 of 5
How many bits are needed to represent the denary value 200 exactly?
200 in binary is 11001000, which is 8 bits. The 7-bit maximum is 127; 8-bit maximum is 255.
Question 5 of 5
Which statement correctly describes a nibble?
A nibble is 4 bits -- exactly half a byte. One nibble maps directly to one hexadecimal digit (0-F).
Section 2: Written questions
Write a full answer in your notebook or on paper before checking against the lesson notes.
Written question 1
Convert the binary number 11001101 to denary. You must show all working, including the place values used. A correct answer without working will score zero.
3 marks
Written question 2
Convert denary 187 to hexadecimal. Show all steps of your working clearly.
4 marks
Written question 3
Explain why hexadecimal is commonly used in computing even though computers only process binary. Refer to at least two reasons.
5 marks