What is 9 – 3 ÷ 1/3 + 1 ?

This seemingly simple math problem went viral in Japan after a study found that only 60% of 20-somethings were able to calculate the correct answer, down from a rate of 90% in the 1980s.

Of course the key is order of operations.

1. Parentheses
2. Exponents
3. Multiplication and Division (left to right)
4. Addition and Subtraction (left to right)

(As the famous mnemonic goes, Please Excuse My Dear Aunt Sally.)

What did you calculate the final answer to be? Let’s let the good people at Mind Your Decisions walk us through it:

Ready to try another?


Here’s another math problem along the same lines. Go check your answer here.

If you’re still in a brain teaser mood but have had enough math for one day, go try to spot the leopard (I promise it’s there).

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Item of the Day

Want to take your math challenges offline? Pick up a copy of The 125 Best Brain Teasers of All Time: A Mind-Blowing Challenge of Math, Logic, and Wordplay.

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