A Story of Numbers — Class 8 MCQs with Answers
Class 8 CBSE Mathematics · Chapter 3
72 practice questions · 24 Easy · 24 Medium · 24 Hard · Updated
Practise the most important Class 8 CBSE Mathematics questions from Chapter 3, "A Story of Numbers". You get 9 timed quizzes made from 72 NCERT-based MCQs, with answers and explanations. The questions are split into 24 Easy, 24 Medium and 24 Hard. Warm up on the basics, then move on to the exam-level questions that top scorers in CBSE Board exams get right.
To score well in "A Story of Numbers", focus on fast problem-solving, formula recall and step-by-step working. Each MCQ here is timed and uses exam-style marking (+4 correct, −1 wrong, 0 skipped). This helps you stay accurate when time is short, just as real papers need. Every question has a short explanation, so a wrong answer becomes a quick lesson. It is the fastest way to fix gaps before a test.
Use this chapter for focused revision. Start with the Easy set to check your basics on A Story of Numbers, then move to Medium and Hard to practise applying them. Your accuracy, streaks and XP save automatically. This chapter also adds to your overall Class 8 Mathematics mastery score. 14 sample questions are solved in full below, with the answer and a worked explanation. Sign in free to start practising.
A Story of Numbers — important questions & MCQs with answers (Class 8 Mathematics)
14 solved questions from this chapter's difficulty levels, each with its answer and explanation.
- Q1Easy
In Roman numerals, what number does the symbol V stand for?
A.5✓ CorrectB.10C.50D.1Answer: A. 5
Explanation: Each Roman symbol has a fixed value no matter where it sits: V always equals 5, unlike X which equals 10 or L which equals 50.
- Q2Easy
In our base-10 system, each place is how many times the place to its right?
A.2B.5C.10✓ CorrectD.100Answer: C. 10
Explanation: In base 10, moving one place to the left multiplies the value by 10: ones become tens, tens become hundreds, and so on.
- Q3Easy
Which base does our everyday number system use?
A.base 5B.base 10✓ CorrectC.base 2D.base 60Answer: B. base 10
Explanation: Our everyday number system groups values in tens at every place, which is exactly what makes it a base-10 (decimal) system.
- Q4Easy
In a base-5 number system, the landmark numbers are the powers of:
A.10B.2C.25D.5✓ CorrectAnswer: D. 5
Explanation: A base-5 system builds up by multiplying by 5 each time, so its landmark numbers 1, 5, 25, 125 … are the powers of 5.
- Q5Easy
In Roman numerals, what number does the symbol X stand for?
A.5B.10✓ CorrectC.100D.50Answer: B. 10
Explanation: Each Roman symbol has a fixed value no matter where it sits: X always equals 10 — it is not V's value of 5 nor L's value of 50.
- Q6Easy
In the number 47561, what is the place value of the digit 5?
A.5B.50C.5000D.500✓ CorrectAnswer: D. 500
Explanation: In 47561, the digit 5 is three places from the right, in the hundreds position, so its place value is 5 × 100 = 500, not just 5 or 50.
- Q7Medium
Write the number 302 in Roman numerals.
A.CCCXIIB.CCCII✓ CorrectC.CDIID.CCIIAnswer: B. CCCII
Explanation: 302 splits into 300 and 2, so CCC + II = CCCII. Dropping a C would wrongly give 202, and using D (500) would be far too large.
- Q8Medium
Which is the correct expanded form of 47561 using powers of 10?
A.(4×10³)+(7×10²)+(5×10¹)+(6×10⁰)B.(4×10⁴)+(7×10³)+(5×10²)+(6×10¹)+(1×10⁰)✓ CorrectC.(4×10⁵)+(7×10⁴)+(5×10³)+(6×10²)+(1×10¹)D.4+7+5+6+1Answer: B. (4×10⁴)+(7×10³)+(5×10²)+(6×10¹)+(1×10⁰)
Explanation: Each digit's value is digit × 10 to the power of its place, counted from 0 at the right: 47561 = (4×10⁴)+(7×10³)+(5×10²)+(6×10¹)+(1×10⁰).
- Q9Medium
In the Egyptian system 324 = 100+100+100+10+10+1+1+1+1. How many symbols are drawn in all?
A.7B.3C.324D.9✓ CorrectAnswer: D. 9
Explanation: There are three 100-symbols, two 10-symbols and four 1-symbols: 3 + 2 + 4 = 9 symbols in total — not the digits of 324 itself.
- Q10Medium
Express the number 143 in base 5.
A.1033✓ CorrectB.1043C.133D.10033Answer: A. 1033
Explanation: 143 = (1×125) + (0×25) + (3×5) + 3 = 1033 in base 5 — the 0 marks that there are no 25s, and it cannot be dropped.
- Q11Medium
Write the number 715 in Roman numerals.
A.DCCXIVB.DCCXV✓ CorrectC.CDXVD.DCCVXAnswer: B. DCCXV
Explanation: 715 splits into 700, 10 and 5, so DCC + X + V = DCCXV. Writing IV instead of V for the last digit gives 714, one too few.
- Q12Hard
What is V × L (that is, 5 × 50 = 250) written in Roman numerals?
A.LLB.CLC.CCCD.CCL✓ CorrectAnswer: D. CCL
Explanation: 5 × 50 = 250 = 200 + 50 = CC + L = CCL. Writing only CL (150) is missing a full hundred.
- Q13Hard
In base 2, the place values read from the right are:
A.1, 2, 4, 8, 16, …✓ CorrectB.1, 2, 3, 4, 5, …C.1, 5, 25, 125, …D.1, 10, 100, …Answer: A. 1, 2, 4, 8, 16, …
Explanation: Binary place values, read from the right, are the powers of 2: 1, 2, 4, 8, 16 and so on.
- Q14Hard
A key advantage of the Hindu (positional) system over the Roman system is that it:
A.uses fewer symbols onlyB.makes arithmetic easy using place value and zero✓ CorrectC.cannot represent large numbersD.has no need for digitsAnswer: B. makes arithmetic easy using place value and zero
Explanation: Place value plus a zero symbol let the Hindu system carry and borrow easily during arithmetic, something the purely additive Roman system cannot do.
Key concepts: A Story of Numbers (Class 8 Mathematics)
This chapter tells how humans learned to write numbers, from tally marks and additive systems like the Roman numerals to the powerful place-value system we use today. The big idea is a base: each system builds on landmark numbers that are powers of a chosen number n. You compare the Egyptian base-10, base-5 and Babylonian base-60 systems, meet binary (base 2), and see why the Hindu positional system with a zero made arithmetic easy.
- Number system
- A set of symbols and rules for writing numbers. Different civilisations built very different systems, but each one records the same counting numbers.
- Additive (tally) systems
- Early systems where a number is the sum of its symbols, such as sticks or the Roman numerals; there is no idea of place, so large numbers need many symbols.
- Roman numerals
- The symbols I=1, V=5, X=10, L=50, C=100, D=500, M=1000, combined by adding — with a smaller symbol before a larger one meaning subtraction (IV=4, IX=9, XL=40).
- Landmark numbers
- The special sizes a system groups by. In every base-n system they start at 1 and each is n times the previous, so they are the powers of n.
- The idea of a base
- A base-n system groups repeatedly in n's; the Egyptian system is base 10, but grouping in fives gives a base-5 system and grouping in sixties a base-60 system.
- Base 10 (decimal)
- Our everyday system, where each place is worth ten times the place to its right: ones, tens, hundreds, thousands, matching the powers of 10.
- Base 2 (binary)
- A system using only the digits 0 and 1, with place values 1, 2, 4, 8, 16 …; computers use it because a switch has just two states, on and off.
- Positional (place value)
- A system in which a digit's value depends on its position, so the same ten digits can write any number — unlike an additive system.
- Role of zero
- A place-holder that marks an empty place so the other digits keep their value; without it 305 and 35 could not be told apart. This was a major Indian contribution.
- Converting to a base
- To write a number in base n, repeatedly divide by n and read the remainders from bottom to top; to read it back, multiply each digit by its place value and add.
- Egyptian base-10 system
- An additive system whose landmark numbers 1, 10, 100, 1000 are powers of 10, drawn with a special symbol for each; the count of each symbol builds the number.
- Why the Hindu system won
- Place value plus a zero make carrying, borrowing and large numbers simple, which is why the Hindu–Arabic system replaced additive systems worldwide.
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What are the key concepts in Class 8 Mathematics A Story of Numbers?+
This chapter tells how humans learned to write numbers, from tally marks and additive systems like the Roman numerals to the powerful place-value system we use today. The big idea is a base: each system builds on landmark numbers that are powers of a chosen number n. You compare the Egyptian base-10, base-5 and Babylonian base-60 systems, meet binary (base 2), and see why the Hindu positional system with a zero made arithmetic easy. Key ideas include Number system, Additive (tally) systems, Roman numerals, Landmark numbers, The idea of a base, Base 10 (decimal).
What does Class 8 Mathematics Chapter 3 (A Story of Numbers) cover on XamBaaz?+
It has 72 NCERT-based MCQs on "A Story of Numbers": 24 Easy, 24 Medium and 24 Hard. Together they make 9 timed quizzes, and you never get the same set twice. Every question has an instant explanation. They help you prepare for CBSE Board exams.
Are these "A Story of Numbers" questions free to practise?+
Yes. Sign in with Google to practise "A Story of Numbers" free. Full unlimited access is ₹999/year. One year from the day you pay. You stay in Class 8 till 31 March; on 1 April your account moves up to Class 9 and the rest of your year carries over. No chapter is charged separately.
How should I revise "A Story of Numbers" for the exam?+
Start with the Easy quiz to check your basics, then try Medium and Hard to practise applying them. There are 9 timed quizzes on this chapter, so you can come back for a fresh set instead of one you have seen. Read each explanation, retry the questions you miss, and track your accuracy until it stays high.
Are these "A Story of Numbers" MCQs available with answers?+
Yes. 14 sample questions are shown here in full, each with the correct option and a step-by-step "Why" explanation. Sign in free with Google to start practising, with instant scoring.
Is there negative marking in the "A Story of Numbers" quizzes?+
Yes. The timed quizzes use exam-style marking: +4 for a right answer, −1 for a wrong one and 0 for a skip. MHT-CET and CBSE board papers have no negative marking. Our mocks for those are scored their way.
What are the important questions from A Story of Numbers (Class 8 Mathematics)?+
The questions that matter most test Number system, Additive (tally) systems, Roman numerals, Landmark numbers, The idea of a base, Base 10 (decimal). This page shows 14 solved important MCQs with answers and explanations. Sign in to practise all 72 questions on the chapter as timed quizzes.
Is there an online quiz for A Story of Numbers?+
Yes — Class 8 Mathematics A Story of Numbers has timed online quizzes at Easy, Medium and Hard levels, with instant scoring and a worked explanation on every question. The first quiz on the chapter is free.