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# 230 - 220 x 0.5 = 5!

One for maths geeks.

Without giving it away, do you think
• it's right, but you're not sure what's clever about it?
• it's right, but you have to have a pretty good understanding of maths to know why?
• it's wrong

«1

• Beardface said:
It's wrong.
That didn't take long! Can you say why you think it's wrong?  (For reference, it isn't).
• Chizz said:
Beardface said:
It's wrong.
That didn't take long! Can you say why you think it's wrong?  (For reference, it isn't).
BODMAS would suggest it is and the answer is 120.

230 - (220*0.5)
• Beardface said:
Chizz said:
Beardface said:
It's wrong.
That didn't take long! Can you say why you think it's wrong?  (For reference, it isn't).
BODMAS would suggest it is and the answer is 120.

230 - (220*0.5)
• So the order you should do your calculations in is:

• Brackets
• Indices
• Division and Multiplication (start on the left and work them out in the order that you find them)
• Addition and Subtraction (when only addition and subtraction are left in the sum, work them out in the order you find them - starting from the left of the sum and working towards the right)
Not sure if the ! At the end.
• Chizz said:
Beardface said:
Chizz said:
Beardface said:
It's wrong.
That didn't take long! Can you say why you think it's wrong?  (For reference, it isn't).
BODMAS would suggest it is and the answer is 120.

230 - (220*0.5)
Yes, although that's commonly considered a computer science formulation, not maths....
• According to BODMAS it's wrong. You need to do the multiplication first before the subtraction.
• Sage said:
According to BODMAS it's wrong. You need to do the multiplication first before the subtraction.

• ! is a command used in computing and not really maths
• wrong for me
You have to be a bit of a maths geek to spot it.  But the answer really is 5!
• Chizz said:
Sage said:
According to BODMAS it's wrong. You need to do the multiplication first before the subtraction.
Only if you have brackets for the 230 - 220, that would make it 5.

Because you don't the answer has to be 120.

It is the same with something like 2 + 3 x 4. Some people might say it's 20, but it's not, the answer is 14.
• Sage said:
Chizz said:
Sage said:
According to BODMAS it's wrong. You need to do the multiplication first before the subtraction.
Only if you have brackets for the 230 - 220, that would make it 5.

Because you don't the answer has to be 120.

It is the same with something like 2 + 3 x 4. Some people might say it's 20, but it's not, the answer is 14.
I agree with everything you have posted here.  And I can also confirm that the answer is 5!
• most people don’t understand what the ! means.

So no great surprise most people are using Bodmas rules.
• 5! = 5x4x3x2x1 =120

• Always multiply first
• Chizz said:
Sage said:
Chizz said:
Sage said:
According to BODMAS it's wrong. You need to do the multiplication first before the subtraction.
Only if you have brackets for the 230 - 220, that would make it 5.

Because you don't the answer has to be 120.

It is the same with something like 2 + 3 x 4. Some people might say it's 20, but it's not, the answer is 14.
I agree with everything you have posted here.  And I can also confirm that the answer is 5!
Okay, care to explain to us what the exclamation mark means at the end of the answer?
• Sage said:
Chizz said:
Sage said:
Chizz said:
Sage said:
According to BODMAS it's wrong. You need to do the multiplication first before the subtraction.
Only if you have brackets for the 230 - 220, that would make it 5.

Because you don't the answer has to be 120.

It is the same with something like 2 + 3 x 4. Some people might say it's 20, but it's not, the answer is 14.
I agree with everything you have posted here.  And I can also confirm that the answer is 5!
Okay, care to explain to us what the exclamation mark means at the end of the answer?
Factorial
• Chizz said:
Sage said:
Chizz said:
Sage said:
Chizz said:
Sage said:
According to BODMAS it's wrong. You need to do the multiplication first before the subtraction.
Only if you have brackets for the 230 - 220, that would make it 5.

Because you don't the answer has to be 120.

It is the same with something like 2 + 3 x 4. Some people might say it's 20, but it's not, the answer is 14.
I agree with everything you have posted here.  And I can also confirm that the answer is 5!
Okay, care to explain to us what the exclamation mark means at the end of the answer?
It means factorial.  You multiply the number by each of the whole numbers that are smaller than it to come up with a product.

Examples: 3! is 3x2x1 = 6.
4! is 4x3x2x1 = 24.
5! = 5x4x3x2x1 = 120.
Okay, thank you.

So with the answer being 5! does that not mean that the real answer is still 120?
• Yes but 5! = 120 = 5! = 6x20 = 5! = 10x12 = 5!

As far as I see it, it is the same therefore if you put 120 or 5! It makes no difference. It is the same.
• Sage said:
Chizz said:
Sage said:
Chizz said:
Sage said:
Chizz said:
Sage said:
According to BODMAS it's wrong. You need to do the multiplication first before the subtraction.
Only if you have brackets for the 230 - 220, that would make it 5.

Because you don't the answer has to be 120.

It is the same with something like 2 + 3 x 4. Some people might say it's 20, but it's not, the answer is 14.
I agree with everything you have posted here.  And I can also confirm that the answer is 5!
Okay, care to explain to us what the exclamation mark means at the end of the answer?
It means factorial.  You multiply the number by each of the whole numbers that are smaller than it to come up with a product.

Examples: 3! is 3x2x1 = 6.
4! is 4x3x2x1 = 24.
5! = 5x4x3x2x1 = 120.
Okay, thank you.

So with the answer being 5! does that not mean that the real answer is still 120?
The answer is 5! or 120 or anything else that's "correct".
• bellz2002 said:
Yes but 5! = 120 = 5! = 6x20 = 5! = 10x12 = 5!

As far as I see it, it is the same therefore if you put 120 or 5! It makes no difference. It is the same.
Yes, that's right.  But the equation gives the answer 5! And that is, de facto, correct.
• Good question.
all comes down to if you know the difference between 5 and 5!
• Depends how it is written.

Does bodmas come into it if you just put the figures into a calculator....no.

That being the case the answer is 5.

If you were going it as a proper maths equation then the answer is 120.