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03rd Jul 2017

This mathematical puzzle is melting people’s brains on a Monday morning

This is really, really tough...


Start your week on fire (not literally).

Monday morning. Traditionally not the time of the week when anyone is at their sharpest.

But BBC’s Today show on Radio 4 decided that this particular Monday was the perfect time to launch an excellent new mathematical puzzle feature.

It’s f*****g hard though. And they won’t be revealing the definitive answer until 6am on Tuesday morning, so it could plague you for the next 24 hours.

So here goes….

Take the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9. Insert the fewest numbers of plusses and minuses wherever you want to get to a grand total of 100.

You must keep the numbers in that order, however, though you can combine numbers as long as they stay in sequence (for example 4, 5 can become 45).

The BBC (helpfully) gave an example of how to complete it using six plusses and minusses: 1 + 2 + 34 – 5 + 67 – 8 + 9 = 100.

We have managed to do it using fewer plusses and minuses than that. But we’ll have to wait until tomorrow to see if that’s as low as it can go.

Good luck.