Last year the internet was set ablaze by a maths problem shared on Twitter which seemingly had two different answers.
Which was right and which was wrong? Nobody could work it out. (You can read more about it here if you're curious).
But fast forward to today and another maths problem is causing a stir online and this time it's all to do with the method itself, not the answer.
A user named @ABlondeAvocado shared a post asking people to use mental maths to solve 18x5 and the tweet quickly went viral.
She wrote: "Math teacher with a question: Using only mental math, solve 18x5.
"What steps did you take in your head to get to the answer?"
She continued to say: "No judgment on how you get there. I did this and took probably the most complicated path but it doesn’t matter because I landed at the answer."
Many people responded and it was fascinating to see how they took different routes to all come out with the answer of 90.
The original poster shared her own method, explaining how she started by turning 18 into 20, then doing 20 x 5 = 100.
"Then multiplied the 2s that I added in order to subtract from the product 2x5= 10 100 - 10 = 90.
"A long way to get there, but I get there."
A different user replied: "18÷2=9×10=90. I always do 5x like that."
While someone else said: "10x18 = 180. Divide by 2. 90."
And another explained they had done: "5*10 + 5*8 = 50+40 = 90 (learnt time tables by rote as a kid so brain doesn't even come into it)."
While a fourth added: "Simplify it by changing it from x5 to x10 like this: 18 x 5 = 9 x 10 = 90.
"A divide by 2 is much easier than a times by 5, especially when you get into 3 digit numbers. 876 x 5 = 438 x 10 = 4380
"Of course you do need to know your 2 times table..."
How would you have worked out the maths problem? Let us know in the comments below.
