Simple Maths

[Addicted to music]

I was tought at school that BOMDAS applies:

 

Bracket 

Of

Multiplication 

Division 
Addition 

Subtraction 

 

This is what BOMDAS represents.   Easy enough, and its logical.

 

But somehow when you enter the question into the calculators or Apps on a phone that has bracket function, It gives you a totally different answer.   For example this:

 

8÷2(2+2)=

 

Put this in any calculator on phone or a app comes out to 16.   People think that division comes before multiplication;  not according to BOMDAS, and then there's other interpretation of it such as BODMAS???  Google it and you'll see.   

 

How does a number on the left that gets divided on by the total numeric product value on the right come out with an answer that's larger than the original number on the left of the above numeric requirement?   Seriously what logic are we thinking here where all the apps for calculators get it so wrong.   when i was doing this at school, the teacher told us to not use a calculator as its doing what you're telling it to do as you enter the sequences, so true even for this case, even though it has perenthesis function. 

 

Hopefully some maths expert will confirm or prove me wrong 

[sakabatou]

Not a maths expert, but I was taught that multiplication and division as group have equal precedence, as do addition and subtraction. If they both appear, you go left to right

Edited October 26, 2024 by sakabatou
clarity

[Addicted to music]

The fraction equivalent: 

 

 

 

[VanArn]

On my Casio fx-82 AU Plus calculator there isn't a problem. Answer is 1.  However, I sometimes do come across errors when I muck up a sequence when doing a calculation.

[Addicted to music]

3 minutes ago, VanArn said:

On my Casio fx-82 AU Plus calculator there isn't a problem. Answer is 1.  However, I sometimes do come across errors when I muck up a sequence when doing a calculation.

 

The trusted Casio FX82,  cant go wrong with them. 

[aechmea]

The answer is 16.

 

If you want the answer to be 1 then the question needs to be written as

 

8 ÷ (2 x (2+2)) = 1

 

Which is different to 8 ÷ 2 x (2+2) = 8 ÷ 2 x 4 = 4 x 8 ÷ 2 = 4  ÷ 2 x 8  = 16

 

Edit: note the extra set of parentheses.

Edited October 26, 2024 by aechmea

[aechmea]

12 minutes ago, Addicted to music said:

 

The trusted Casio FX82,  cant go wrong with them. 

Obviously you can if it gets it wrong.

 

It will however get the right answer if the operations are done in the correct order.

[doogie44]

I was taught maths in school: epic fail.

 

I bought a calculator when I was an adult: another epic fail (except for simple addition)

 

IRL: "There are three kinds of people in the world; those thaqt understand maths and those that don't!"

 

 

[Addicted to music]

53 minutes ago, aechmea said:

The answer is 16.

 

If you want the answer to be 1 then the question needs to be written as

 

8 ÷ (2 x (2+2)) = 1

 

Which is different to 8 ÷ 2 x (2+2) = 8 ÷ 2 x 4 = 4 x 8 ÷ 2 = 4  ÷ 2 x 8  = 16

 

Edit: note the extra set of parentheses.

 

BOMDAS

 

Its done in this order first: Brackets, Of, Multiplication, Division, Addition, Subtraction.  Extra perenthesis defines it but not needed.  (2+2)=4.   2×4=8.    so 8÷8=1.  Note the rule:  brackets 1st,  multiplication, then division.    

 

As indicated, the left Number that gets divided by the product on the right can never be higher.   Go my post above with the fraction equivalent 

Edited October 27, 2024 by Addicted to music

[doogie44]

Even reading about these rules gives me a bad feeling deep down inside...must be PTSD?

 

My mentor loved maths; he told me that he especially loved algebra:

"It was easy--I got 'x' on the first day! Then, they changed it...". Exactly. 

[sir sanders zingmore]

3 hours ago, Addicted to music said:

BOMDAS

Never heard of it. I was always taught BODMAS

[aechmea]

3 hours ago, Addicted to music said:

 

BOMDAS

 

Its done in this order first: Brackets, Of, Multiplication, Division, Addition, Subtraction.  Extra perenthesis defines it but not needed.  (2+2)=4.   2×4=8.    so 8÷8=1.  Note the rule:  brackets 1st,  multiplication, then division.    

 

As indicated, the left Number that gets divided by the product on the right can never be higher.   Go my post above with the fraction equivalent 

Rubbish.  This is simply incorrect.

 

Trust me, I am a mathematician; been doing it since well before some dill invented BODMAS, which clearly doesn't help.

 

1.  Solve the parentheses

2. Then do the multiplication and division left to right.

3.  Then do the addition and subtraction left to right.

 

You do not divide the right hand product into the leading number.  Whoever taught you that is dead wrong.

 

BODMAS or BOMDAS are fine if you realise that DM and MD are equivalent.

 

The extra set of brackets are most certainly needed if you want the answer to be 1.

 

[In computing it is wise to do the multiplies first since if you do the divides first you can end up with bit stripping.]

 

[When I went to primary school, the acronym of BODMAS or BOMDAS or whatever either didn't exist or wasn't used.  We just learnt the order in which to do things.  First heard about an acronym from my wife (teacher) and my son (PhD in pure maths) a few years ago.]

 

 

Edited October 27, 2024 by aechmea
Clarity

[doogie44]

I invariably ended up with a MAD SOB

[VanArn]

If the subject of the discussion is an anagram, then I offer SAD MOB.

[Addicted to music]

2 hours ago, aechmea said:

Rubbish.  This is simply incorrect.

 

Trust me, I am a mathematician; been doing it since well before some dill invented BODMAS, which clearly doesn't help.

 

1.  Solve the parentheses

2. Then do the multiplication and division left to right.

3.  Then do the addition and subtraction left to right.

 

You do not divide the right hand product into the leading number.  Whoever taught you that is dead wrong.

 

BODMAS or BOMDAS are fine if you realise that DM and MD are equivalent.

 

The extra set of brackets are most certainly needed if you want the answer to be 1.

 

[In computing it is wise to do the multiplies first since if you do the divides first you can end up with bit stripping.]

 

[When I went to primary school, the acronym of BODMAS or BOMDAS or whatever either didn't exist or wasn't used.  We just learnt the order in which to do things.  First heard about an acronym from my wife (teacher) and my son (PhD in pure maths) a few years ago.]

 

 

 
the delema is O.  O is mutliplication.  Don’t care if you’re a PHD in maths or whether your family member teaches maths.  Multiplication comes b4 any division. Yes take the maths and do from left to right.  
Whether it’s BOMDAS or BODMAS or PEMDAS the O comes first b4 division or multiplication as it’s referring to power, and power is multiplication.  
 

Quote: 

 

PEMDAS = Parentheses, Exponents, Multiplication, Division, Addition, Subtraction

Whereas BIDMAS and BODMAS = Brackets, Indices (Orders), Division, Multiplication, Addition, Subtraction

And GEMDAS = Groupings, Exponents, Multiplication, Division, Addition, Subtraction

 

 

not above multiplication comes before division; ALWAYS

[aechmea]

2 hours ago, Addicted to music said:

power is multiplication.  

No it isn't.

8**2 = 64

8*2 = 16

 

I honestly don't understand why you asked for help and then argue that black is white time and time again.

 

3 hours ago, Addicted to music said:

Don’t care if you’re a PHD in maths or whether your family member teaches maths

Maybe you should.

 

The correct way that has been described here has been a maths convention since the 1600s and BODMAS the acronymn, or whatever, was first used 200 years ago, according to the world-wide-interweb.

 

[sir sanders zingmore]

@aechmea is correct on this. 
 

[Addicted to music]

1 hour ago, sir sanders zingmore said:

@aechmea is correct on this. 
 

 

Is he?

https://www.google.com/search?cs=0&sca_esv=12c32a9e01a03173&sxsrf=ADLYWIKcMh4BBIbUH9lrYI7x7sBHnY44-A:1730025761476&q=What+is+the+BODMAS+rule+in+Australia%3F&sa=X&ved=2ahUKEwj3odGXsK6JAxWP-DgGHb2QIXIQzmd6BAgEEAY&biw=1680&bih=962&dpr=2

 

It stipulates that calculations in brackets must be made first, followed by calculations involving indices (powers, exponents), then multiplication and division (working from left to right), and lastly, addition and subtraction (also in order from left to right).

 

Note the order of  muliplication and division.....and not division and multiplication....

 

Google it and youll get it stated both ways,.   Yes you will get 16 if you use a calculator or a program or app thats not taken the above in consideration.  Note also that any calculator or program will be influence on whats been typed 1st.  And then you see  a Post above comes to 1 with a Casio calculator....

 

 

 

[Addicted to music]

1 hour ago, aechmea said:

No it isn't.

8**2 = 64

8*2 = 16

 

 

 

 

 

8 to the power of 2 equals 64.   Also 8x8=8*2=64....  

 

 

 

 

[sir sanders zingmore]

Usual symbol for power is ^
Usual symbol for multiplication is *.
 

8*2 = 16

8^2 = 64

 

honestly can we argue about vinyl vs digital, it’s much more fun
 

[Addicted to music]

12 minutes ago, sir sanders zingmore said:

Usual symbol for power is ^
Usual symbol for multiplication is *.
 

8*2 = 16

8^2 = 64

 

honestly can we argue about vinyl vs digital, it’s much more fun
 

 

and then we have 8 X 2 = 16.   fun isnt it....  It depends where you are in the world and how it was taught and what symbal was used!  thats why the above problem is so ambiguous....

[LogicprObe]

 

Stop worrying.............AI will do it all for us.

 

No probs!

[sir sanders zingmore]

6 minutes ago, Addicted to music said:

 

and then we have 8 X 2 = 16.   fun isnt it....  It depends where you are in the world and how it was taught and what symbal was used!  thats why the above problem is so ambiguous....

The problem isn’t ambiguous at all, it’s just deliberately badly stated. 
If it was:

Use the BODMAS convention to solve 8÷2(2+2)= 

 

Or 

Use the BOMDAS convention to solve 8÷2(2+2)= 

 

Then it would be unambiguous. 

[Martykt]

47 minutes ago, sir sanders zingmore said:

honestly can we argue about vinyl vs digital, it’s much more fun

12 x 45 =

[David A]

I'll shout a beer to anyone who can solve the Navier-Stokes Equation.