Missing Operator

Missing Operator problems present an arithmetic expression with one operator missing (indicated by '?'). You must determine which operator (+, -, ×, ÷) makes the equation true. These problems test your ability to test multiple possibilities and understand operator effects on expression values.

10Worksheets
200+Practice Questions
MediumDifficulty
2-3 hoursHours to Master

Introduction to Missing Operator

Missing Operator problems present an arithmetic expression with one operator missing (indicated by '?'). You must determine which operator (+, -, ×, ÷) makes the equation true. These problems test your ability to test multiple possibilities and understand operator effects on expression values.

Prerequisites

Basic arithmetic operations BODMAS rules Trial and error testing Equation evaluation skills
Why This Matters: Missing Operator problems appear in 1-2 questions in SSC CGL and Banking PO exams. They test operator analysis and trial-and-error reasoning.

How to Solve Missing Operator Problems

1

Step 1: Identify the position of the missing operator (between which numbers)

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Step 2: Test each operator (+, -, ×, ÷) in that position

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Step 3: For each operator, evaluate the entire expression using BODMAS

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Step 4: Compare the result with the given right-hand side

5

Step 5: The operator that makes the equation true is the answer

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Step 6: If multiple operators work, check if the problem expects a specific one

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Step 7: Present the correct operator

Pro Strategy: Test each operator systematically. Remember that multiplication and division have higher precedence than addition and subtraction, which affects the evaluation order. Calculate the expression correctly for each candidate operator.

Example Problem

Example: What operator should replace '?' to make 8 ? 4 × 2 = 16? Solution: Step 1: Expression: 8 ? 4 × 2 = 16 Step 2: Test +: 8 + 4 × 2 = 8 + 8 = 16 ✓ Step 3: Test -: 8 - 4 × 2 = 8 - 8 = 0 ✗ Step 4: Test ×: 8 × 4 × 2 = 64 ✗ Step 5: Test ÷: 8 ÷ 4 × 2 = 2 × 2 = 4 ✗ Step 6: Only + works Answer: +

Pro Tips & Tricks

  • Write the expression with the operator placeholder
  • Test operators in order: +, -, ×, ÷
  • Use BODMAS correctly - multiplication and division before addition/subtraction
  • For ÷, check if division yields an integer (or handle decimals)
  • If multiple operators work, the problem may expect the first one or have additional constraints
  • Sometimes the missing operator is between the first two numbers, sometimes between later numbers

Shortcut Methods to Solve Faster

If result is larger than the numbers, × or + are likely
If result is smaller, - or ÷ are likely
Test the most promising operator first
Use the inverse operation to find the required operator

Common Mistakes to Avoid

Forgetting operator precedence (evaluating left to right without BODMAS)
Testing operators in wrong order and missing the correct one
Miscalculating for ÷ (especially with non-integer results)
Not considering that the missing operator could be at different positions

Exam Importance

Missing Operator is an important topic for various competitive exams. Here's how frequently it appears:

SSC CGL
1-2 questions
BANKING PO
1-2 questions
RAILWAYS RRB
1-2 questions
INSURANCE
1-2 questions

Ready to Master Missing Operator?

Start with Worksheet 1 and work your way up to expert level! Each worksheet includes:

20 practice questions
Detailed solutions
Step-by-step explanations
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