Cambridge IGCSE · Computer Science (0478)

Number systems: Practice Questions

5 multiple-choice questions marked as you go, and 5 written questions with worked solutions. All on Number systems.

10 questions24 marksFree, no account

Question 1

1 mark

An 8-bit register contains the binary value \(00111100_2\). What is the result in binary after a logical right shift of 3 places is performed?

Question 2

1 mark

What is the hexadecimal representation of the denary number \(455\)?

Question 3

1 mark

A computer uses 8-bit registers to store positive integers. What is the result of the following binary addition?

\(10101100_2 + 01100011_2\)

Question 4

1 mark

In the context of computer data representation, how many bits of information are represented by the hexadecimal value \(C4_{16}\)?

Question 5

1 mark

A CPU uses 8-bit registers to store positive integers. It attempts to add the binary numbers \(11110000_2\) and \(00010101_2\).
Which statement correctly describes the result of this operation?

Question 6

2 marks

Convert the 8-bit binary number \(11100101_2\) into its equivalent hexadecimal representation.

Write your answer out first, then check it against the worked solution.

Question 7

3 marks

Convert the denary number 219 into its equivalent hexadecimal representation.

Write your answer out first, then check it against the worked solution.

Question 8

5 marks

Calculate the 8-bit binary addition of \(10011000_2\) and \(11001101_2\). Explain why the resulting value would cause an overflow error in an 8-bit register.

Write your answer out first, then check it against the worked solution.

Question 9

4 marks

a) Convert the binary number $$11010110_2$$ to its denary (base 10) equivalent.

b) An 8-bit register stores the positive binary number $$10110100_2$$. Another 8-bit register stores $$01001101_2$$. Perform the binary addition of these two numbers and state the result in 8-bit binary. Convert the 8-bit binary sum to its denary equivalent. Indicate if an overflow error occurs and explain why.

Write your answer out first, then check it against the worked solution.

Question 10

5 marks

An 8-bit CPU performs addition on two positive binary integers stored in its registers.

Register 1: \( 01010101_2 \)
Register 2: \( 10101011_2 \)

a) Calculate the binary sum of the values in Register 1 and Register 2. Show your working. [2]
b) Convert the resulting binary sum into its denary equivalent. [2]
c) Explain why the CPU would flag an error if it attempted to store the result of the denary calculation \( 200 + 100 \) in a single 8-bit register. [1]

Write your answer out first, then check it against the worked solution.

* The content provided by thinka is generated by AI and may not always be accurate or up-to-date. Please use it as a supplementary resource and verify with official materials.

You've seen the model answer. Now get yours marked.

This page can show you how a good answer looks. It cannot tell you what your answer was missing. thinka marks your written work against the real mark scheme in about 15 seconds.

Get My Answers Marked Back to the notes

Want more questions like these? Get a fresh set on this topic, graded as you go.