How to Calculate Using BODMAS: Step-by-Step Guide (India)

If you have ever argued with a friend over the answer to a maths puzzle forwarded on WhatsApp, you have already met the BODMAS rule — even if you did not call it that. In Indian schools, from the CBSE and state boards to competitive exams like SSC, banking, and railways, BODMAS is the single agreed-upon system that decides which operation to do first in a long expression. Without it, the same sum could produce five different answers depending on who is solving it.

This step-by-step guide shows you exactly how to calculate any expression using BODMAS, with fully worked Indian examples, a quick-reference table, the mistakes students most often make, and expert tips from how the rule is actually tested in Indian classrooms and exams.

Key takeaway: BODMAS is not about being clever — it is a shared rulebook. Once everyone agrees to solve Brackets, then Orders, then Division/Multiplication, then Addition/Subtraction, every correct solver reaches the same single answer.

What Does BODMAS Stand For?

BODMAS is an acronym that fixes the sequence of operations in arithmetic. Each letter represents a stage you must clear before moving to the next. The full form, as taught in the NCERT textbooks used by CBSE schools across India, is straightforward but worth memorising precisely because the order is the whole point.

Two things trip people up. First, the “O” does double duty: in most Indian textbooks it means “Of/Orders”, where “orders” covers exponents and square roots, and “of” means multiplication (“half of 200” is 100). Second, D and M are equal in rank, and so are A and S — you never do all division before all multiplication. Instead you sweep left to right within each pair.

How to Calculate Using BODMAS: The Steps

Here is the reliable four-step method you can apply to any expression, whether it is a Class 6 homework sum or a quantitative-aptitude question in a bank exam.

1. Solve the brackets first. Work from the innermost bracket outward — curly { }, then square [ ], then round ( ) if all three appear.
2. Clear the orders. Evaluate powers, square roots, and any “of” expressions.
3. Do division and multiplication together, left to right. Whichever comes first as you read from the left is done first.
4. Do addition and subtraction together, left to right. Again, follow reading order.

Worked Example 1: A Class 7 Style Sum

Solve: 12 + 6 ÷ 3 × 2

• No brackets, no orders.
• Division and multiplication, left to right: 6 ÷ 3 = 2, then 2 × 2 = 4.
• Now addition: 12 + 4 = 16.

A common wrong answer is 12, which happens when someone does 3 × 2 = 6 first, then 6 ÷ 6 = 1, then 12 + 1. That breaks the left-to-right rule for division and multiplication.

Worked Example 2: A Shopkeeper’s Bill

Imagine a kirana shop in Pune. A customer buys 3 packets of biscuits at ₹20 each and 2 bottles of oil at ₹150 each, then gets a flat ₹50 discount. The bill expression is: 3 × 20 + 2 × 150 − 50.

• Multiplication first, left to right: 3 × 20 = 60, then 2 × 150 = 300.
• Addition and subtraction, left to right: 60 + 300 = 360, then 360 − 50 = ₹310.

This is why BODMAS is not just an exam trick — billing software, GST invoices, and spreadsheets all follow exactly this order internally.

Worked Example 3: With Brackets and Orders

Solve: 4 + [ 2 × ( 3² − 4 ) ]

• Innermost bracket, orders first: 3² = 9, so ( 9 − 4 ) = 5.
• Square bracket: 2 × 5 = 10.
• Addition: 4 + 10 = 14.

Benefits of Using BODMAS

The biggest benefit is consistency: BODMAS guarantees that a student in Chennai, an accountant in Surat, and a spreadsheet in a Bengaluru office all arrive at the same answer for the same expression. It removes ambiguity from written maths, which matters enormously in exams where marks are awarded for the exact correct value. It also builds a mental discipline that carries into algebra, where the same priority rules apply to variables. For competitive-exam aspirants, mastering BODMAS speeds up quantitative-aptitude sections because you stop second-guessing which step comes next. Finally, it mirrors how calculators and programming languages evaluate expressions, so understanding it makes technology more predictable rather than mysterious.

Challenges and Limitations

BODMAS is a convention, not a law of nature, and that causes occasional confusion. The rule does not tell you what to do when an expression is genuinely ambiguously written — for example, the infamous 8 ÷ 2(2+2) puzzle divides opinion precisely because implied multiplication (the number stuck to a bracket) is not clearly ranked in the basic BODMAS taught in schools. Different regions also use different acronyms (PEMDAS in the US), which can unsettle students who study foreign material. BODMAS also says nothing about functions like sine, logarithms, or factorials, which appear in higher classes and need their own conventions. The safest habit is to add brackets generously when you write expressions yourself, removing any doubt.

Common Mistakes to Avoid

1. Doing division before multiplication automatically. They are equal; go left to right. Treating “D before M” as a hard rule produces wrong answers.
2. Doing addition before subtraction automatically. Same trap — A and S are equal in rank and solved left to right.
3. Ignoring the “of”. “½ of 200 + 50” means (100) + 50 = 150, because “of” is done at the orders stage before addition.
4. Forgetting to work brackets inside-out. When curly, square, and round brackets are nested, always start from the innermost.
5. Mishandling negative signs. A minus sign in front of a bracket flips every term inside once the bracket is removed.
6. Rushing viral puzzles. Most WhatsApp “99% get this wrong” sums are simply BODMAS done too fast; slow down and take one stage at a time.

Best Practices and Expert Recommendations

1. Rewrite the expression in stages. Copy it down after each step so you can see exactly what you simplified.
2. Underline the operation you are about to do. This stops you from skipping ahead to addition too early.
3. Use brackets when you write your own sums. Clear brackets prevent 90% of disputes and mirror how spreadsheets expect input.
4. Verify with a BODMAS calculator. After solving by hand, confirm with a free online tool so you catch slips before an exam does.
5. Practise with Indian exam papers. SSC, banking, and CBSE sample papers reuse the same BODMAS patterns, so repetition builds speed.
6. Teach it aloud. Explaining a sum to a classmate is the fastest way to lock in the left-to-right rule.

BODMAS vs PEMDAS: The India–US Difference

Indian students sometimes panic when foreign textbooks or YouTube videos say “PEMDAS”. There is nothing to worry about — it is the same order with different names.

Both acronyms produce identical answers. The reordering of D/M and M/D is cosmetic because those operations are equal in priority anyway.

Conclusion

Calculating with BODMAS comes down to patience and order: clear the brackets, settle the orders, sweep through division and multiplication left to right, and finish with addition and subtraction. Every Indian board exam, competitive test, and even the billing engine at your local shop relies on this same sequence. Work through a few examples a day, verify with a free BODMAS calculator, and those “tricky” puzzles stop being tricky at all.

FAQs

What is the correct order in BODMAS?
Brackets, then Orders (powers and roots), then Division and Multiplication left to right, then Addition and Subtraction left to right. Division and multiplication are equal in rank, as are addition and subtraction.

Is BODMAS or PEMDAS used in India?
India uses BODMAS, which is taught from Class 6 in the NCERT and CBSE syllabus. PEMDAS is the American version and gives exactly the same answers.

What does the O in BODMAS mean?
The O stands for Orders, which covers powers (like 5²), square roots, and “of” expressions such as “half of 200”. These are solved right after brackets.

Do you always divide before you multiply in BODMAS?
No. Division and multiplication have equal priority, so you perform whichever appears first when reading the expression from left to right.

Why do WhatsApp maths puzzles have different answers?
Usually because people apply BODMAS too quickly or the puzzle is written ambiguously. Solving one stage at a time and adding brackets removes the confusion.