STEM

# Japanese Viral Math Problem

3 CQ

This math puzzle went viral in Japan some time ago after the media reported that only 60% of 20 year olds could arrive at the correct answer.

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3 Comments
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David B
The correct answer depends on how the formula is written. Thus (9-3)/1/3 + 1 = 19, 9 - (3/13) + 1 = 1, 9 - (3/1/3 + 1) = -1. Since the operand ( ) was not used in the original display a 19, 1 and -1 are possible correct answers. I don't agree with Carol D's answer about the order of operations as one needs to have the necessary order addressed through the operand.
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Gina M
The plant illustration was a very useful way to show dividing fractions. I knew to do the inverse operation and “flip” the fraction but this is a wonderful way of showing why. Thank you.
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Carol D
Actually, if you apply the order of operations, you would address multiplication/division before addition/subtraction anyway. Thus one would need to solve 3 divided by 1/3 first, which is achieved by inverting the fraction and changing divide to multiply resulting in 3 X 3 which equals 9. From there it is quite simple, e.g. 9-9+1.
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