Ready for a brain-teaser that separates speedy thinkers from the rest? Take on the challenge: 11 – 11 × 11 + 11 = ? At first glance it looks like a simple subtraction and addition, but applying the proper order of operations is crucial. Will you rush to an incorrect result or pause to multiply first? In this post, we break down every step so you can see why the answer is surprising. Give it a try, then read on for the full explanation—and see if you outsmart this tricky puzzle!
Only a Maths Genius Can Solve This Tricky Puzzle in Just 20 Seconds
Imagine you’re handed this simple-looking equation and told to solve it in under 20 seconds:
- 11 – 11 × 11 + 11 = ?
At first glance, it seems like basic arithmetic. Yet this problem has fooled countless people because it hides a classic pitfall in the order of operations. Will you be among the few who spot the trick immediately?
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Common Mistakes and Why They Happen
Even seasoned math lovers often stumble here. The three biggest missteps are:
Performing Operations Left to Right
Many solvers instinctively calculate “11 – 11 = 0” first, then multiply by 11, and finally add 11. This sequential approach ignores the priority of multiplication.
Overlooking PEMDAS/BODMAS
The mnemonic PEMDAS (Parentheses, Exponents, Multiplication & Division, Addition & Subtraction) or BODMAS in some countries reminds us that multiplication must come before addition or subtraction. In the heat of a timed puzzle, it’s easy to forget.
Rushing Under Time Pressure
A 20-second countdown can push you to jump the gun. Quick reflexes are useful—but only if they’re guided by a clear, methodical process.
By understanding these pitfalls, you’ll know exactly where to pause and apply the correct rule.
Step-by-Step Solution
Identify the Multiplication
- The expression is 11 – (11 × 11) + 11.
Compute 11 × 11
- 11 × 11 = 121.
Rewrite the Expression
- It becomes 11 – 121 + 11.
Perform Subtraction and Addition in Order
- 11 – 121 = –110
- –110 + 11 = –99
So the correct answer is –99.
Share Your Result
Did you arrive at –99 in record time, or did you first get tripped up? Let us know your answer and timing in the comments below. If you enjoyed this challenge, check out more puzzles on our site to keep your brain sharp!
