Simplification and Approximation Formulas, Short Tricks, and Tips

Simplification and Approximation are foundational topics in Quantitative Aptitude. Whether you’re appearing for SSC, Banking, or Railway exams, you will definitely come across 1–2 questions from this topic in almost every shift.
In this blog, we have provided details about the types of questions asked on Simplification and Approximation, along with short notes, formulas, time-saving tricks and tips, and previous year solved questions asked in various examinations.

What Is Simplification and Approximation in Quantitative Aptitude?

Simplification involves solving mathematical expressions accurately using arithmetic operations, while Approximation requires finding the nearest or estimated value of a given expression.

Why Is It Asked in Exams?

These questions test your speed and accuracy in basic operations — addition, subtraction, multiplication, division, percentages, and BODMAS rule. It’s a scoring topic that can save time in the exam.

Skills Required

• Speed Calculation
• Number Sense
• Decimal Handling
• Use of Approximate Values
• Application of BODMAS and estimation logic

Why Is Simplification and Approximation Important in Competitive Exams?

Questions from this section are generally easy and help in building speed and confidence at the beginning of the Quant paper.

Exam	No. of Questions	Difficulty
SSC CGL / CHSL	1–2	Easy
IBPS PO / SBI PO	1–2	Moderate
RRB NTPC / Group D	1	Easy
State PSC / Police	1–2	Moderate

Simplification and Approximation Quantitative Aptitude Short Notes

To score well, candidates should revise the following concepts:

Term	Explanation
BODMAS Rule	Order: Brackets, Orders (powers/roots), Division, Multiplication, Addition, Subtraction
Vinculum	A bar used to group numbers in a complex expression
Estimation	Rounding off values to nearest tens, hundreds, etc., for faster calculation
Approximate Equality	Use of ≈ symbol when exact values are not required
Surds and Decimals	Knowledge of √2 ≈ 1.41, √3 ≈ 1.73, etc., helps in quick estimates

Concepts Used in Simplification and Approximation Questions

Concepts commonly used in Simplification and Approximation questions are as follows:

Concept	Explanation
Use of BODMAS	Always follow this rule in multi-operation expressions
Rounding Rules	Round up ≥ .5, down < .5 for faster approximation
Multiplication Tricks	Break numbers: 98×97 = (100−2)(100−3) = 100² − (2+3)×100 + 6
Common Approximations	√2 ≈ 1.41, √3 ≈ 1.73, π ≈ 3.14, 22/7, e ≈ 2.71
Estimation Logic	Ignore decimal precision unless necessary
Square & Cube Shortcuts	11² = 121, 12² = 144… up to 25² should be memorized

What Are the Types of Simplification and Approximation Questions in Quantitative Aptitude?

Types of questions commonly asked in the exam are as follows:

• Direct Calculation: Use BODMAS to solve exact value
• Approximate Value: Choose the nearest answer from options
• Mixed Operation: Combine %, square roots, brackets, decimals
• Decimal/Surds Simplification: Deal with irrational or decimal expressions
• Missing Term Based: Use simplification to find a missing number

Simplification and Approximation Formulas for Quantitative Aptitude

Solving simplification questions with speed and accuracy requires not just formulas but intense practice too. The formulas that can be used in solving these types of questions are as follows:

• (a + b)² = a² + 2ab + b²
• (a − b)² = a² − 2ab + b²
• a² − b² = (a + b)(a − b)
• Vedic Math multiplication methods
• Convert % to fractions: 25% = 1/4, 50% = 1/2
• Round-off: 497 ≈ 500, 1023 ≈ 1000

Simplification and Approximation Tricks for SSC CGL and Other Exams

Tricks that are useful in solving Simplification and Approximation questions are as follows:

1. Use BODMAS religiously never skip brackets
2. Round-off decimals smartly don’t overcomplicate
3. Break large numbers 98 × 97 = (100−2)(100−3)
4. Convert % to fractions simplifies multiplication
5. Eliminate wrong options smart guessing works
6. Use approximation only when instructed or you may lose marks
7. Memorize common squares and cubes

Solved Simplification and Approximation Questions from 2024–25 Exams

1. Asked in SSC CGL 2024 Tier 1 Shift 2 – Memory-Based

Q: 256 + 439 – 312 × 2 = ?
A: 71
Explanation:
312 × 2 = 624
256 + 439 = 695
695 − 624 = 71

2. From IBPS PO Prelims 2024

Q: Approximate value of √198 × 2.9 = ?
A: 41
Explanation:
√198 ≈ 14.07, 14 × 2.9 ≈ 40.6 ≈ 41

3. Asked in RRB NTPC 2024 Stage 1

Q: (12.8 + 7.2) × 5 = ?
A: 100
Explanation:
12.8 + 7.2 = 20
20 × 5 = 100

4. From Oliveboard Mock Test 2025

Q: (99² – 1) ÷ 10 = ?
A: 980
Explanation:
99² = 9801
9801 − 1 = 9800
9800 ÷ 10 = 980

Simplification and Approximation Concepts for Bank Exams

In Bank exams like IBPS or SBI, questions often combine multiple components percentages, approximations, decimals, and surds into a single complex expression. For example:

Q: Approximate value of (56.2% of 250) + √81 = ?
A:
56.2% of 250 = ~140
√81 = 9
Total ≈ 149

Common Mistakes to Avoid while Solving Simplification and Approximation

Common mistakes to avoid while solving these questions are as follows:

1. Ignoring BODMAS order: Always follow correct sequence
2. Over-approximation: Round-off smartly; don’t distort the value
3. Incorrect square root estimations: Memorize common √ values
4. Skipping intermediate steps: Leads to calculation errors
5. Not verifying final step: Always double-check before marking the answer

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