

How to Convert Between Different Numeral Systems?
The concept of numeral system plays a key role in mathematics and is widely applicable to both real-life situations and exam scenarios. Understanding different numeral systems, such as decimal, binary, and octal, helps students build a strong base for calculations, computer science applications, and logical reasoning.
What Is Numeral System?
A numeral system is a way of writing and expressing numbers using specific symbols or digits, based on certain rules. Each system is characterized by its base (also known as its “radix”) and a set of available symbols. You’ll find this concept applied in areas such as number system maths, computer programming (binary and hexadecimal), and even daily counting or currency systems.
Main Types of Numeral Systems
Let’s look at some important types of numeral systems and how they appear in our daily life and studies:
System | Base | Digits/Symbols Used | Example |
---|---|---|---|
Decimal (Hindu-Arabic) | 10 | 0-9 | 3810 |
Binary | 2 | 0, 1 | 100112 |
Octal | 8 | 0-7 | 478 |
Hexadecimal | 16 | 0-9, A-F | A216 |
Indian Numeral System | 10 | 0-9 | 10,00,000 (Ten Lakh) |
Roman Numeral System | — | I, V, X, L, C, D, M | XIV (14) |
Key Formula for Numeral System
Here’s the standard formula for expressing a number (N) in any numeral system with base ‘b’:
\( N = d_n b^n + d_{n-1} b^{n-1} + ... + d_1 b^1 + d_0 b^0 \)
where each digit \( d_i \) must be equal to or less than \( b-1 \).
Why Do We Use Different Numeral Systems?
Different numeral systems are used because of history, practicality, and the needs of different fields. For example, computers naturally use the binary numeral system (“0” and “1”) because their circuits have only two states (on/off). In India, we use the Indian numeral system for large numbers (lakh, crore), while internationally, the western system is common.
Step-by-Step Illustration: Decimal to Binary Conversion
Let's learn to convert the number 19 from decimal (base 10) to binary (base 2):
1. Divide 19 by 2: quotient 9, remainder 12. Divide 9 by 2: quotient 4, remainder 1
3. Divide 4 by 2: quotient 2, remainder 0
4. Divide 2 by 2: quotient 1, remainder 0
5. Divide 1 by 2: quotient 0, remainder 1
6. Write the remainders from last to first: 100112
So, the decimal number 19 equals 10011 in binary.
Speed Trick for Numeral System Conversions
Here’s a quick way to check if a binary number is even or odd: just look at the last digit. If it’s “1”, the number is odd; if “0”, the number is even. This simple trick helps you answer quickly during competitive exams or MCQs.
Try These Yourself
- Convert 3410 to binary and octal.
- Write 255 as a hexadecimal number.
- What is the value of 11012 in decimal?
- Name the place value in the Indian numeral system for the third position from right.
Frequent Errors and Misunderstandings
- Mistaking the base while converting between numeral systems.
- Mixing up the Indian and International place value systems.
- Forgetting to write remainders in correct order during binary conversion.
Relation to Other Concepts
The idea of numeral system connects closely with topics such as Number System and Place Value. Understanding numeral systems also gives you an edge in Binary Number System for computers, and in learning Roman Numerals for history or competitive quizzes.
Cross-Disciplinary Usage
The numeral system is not only useful in Maths but also plays an important role in Physics, Computer Science, and daily logical reasoning. Students preparing for JEE or NEET will see its relevance in questions related to coding, digital electronics, or even ancient number systems.
Classroom Tip
A quick way to remember the difference between Indian and International numeral system: In the Indian system, periods are grouped as: ones, thousands, lakhs, crores. In the International system, they are: ones, thousands, millions, billions. Vedantu’s teachers often use place value charts to make this distinction crystal clear during live classes.
We explored numeral system—from definition, formula, types, examples, common errors, and its connections to other disciplines. Continue practicing with Vedantu to become confident at solving all kinds of questions involving different numeral systems. Mastery here builds speed not only for Maths questions but also real-world reasoning and computer logic!
Recommended for further reading:
- Indian Number System – Deep dive into India’s unique number grouping.
- Binary Number System – Key for computer science and IT students.
- Place Value – Essential for understanding how numbers are constructed.
- Decimal Number System – The base system used in everyday maths.





