Maths Disagreement

[TulaOfDarkWater]

One person thinks the answer is 165 and the other thinks 67, who is right?

YABU - 165
YANBU - 67

Or what’s the answer if both are wrong?

@PugInTheHouse
No they just haven't read the thread is cancel the cheque

[quote bruffin]@PugInTheHouse
No they just haven't read the thread is cancel the cheque[/quote]
Ie cancel the cheque

@bruffin I am slightly obsessed my maths stuff. There was a great post on FB recently where people were discussing the answer to 40÷0.5

@ChildHeadache

It's 38.

Check no. Of bananas, number of sides and time on clock. And remember bodmas.

I agree. Definitely 38. Bananas worth 3 (actual number shown in pic). Clock worth 2 (number on face). Grey shape worth 11 (total number of sides). Following order of operations rules, sum is 2 + 3 + (3 × 11) So 33 + 5 = 38.

deffo 165

@SomeoneInTheLaaaaaounge

deffo 165

deffo not!

Hi, @SomeoneInTheLaaaaaounge -

It appears you are doing your operations from left to right. Why this is incorrect is the subject of some lively reading on this thread.
The Wikipedia article ‘On the Order of Operations’ is extremely comprehensive. The intro is good.

[quote PugInTheHouse]@bruffin I am slightly obsessed my maths stuff. There was a great post on FB recently where people were discussing the answer to 40÷0.5[/quote]
What is there to discuss?

If it’s the same one I saw the 0.5 was written as a fraction and may people thought that it meant half of forty.

38

Exactly as others have said.

[quote PugInTheHouse]@gettingstuffed there is definitely only one way of doing it, order of operations wasn't necessarily taught properly in schools till about the 80s however you would have been given brackets if not taught it. Do the calculation on a calculator with no brackets and it will give you the correct answer.[/quote]
Ah, the calculator.
This depends enormously on the calculator you use.
My computer (microsoft) calculator does the calculation left to right and ignores BODMAS and gives an answer of 88; whereas my phone calculator DOES use BODMAS and gives the correct answer of 38.

Depressing, huh.

See I like the ones where you have to divide by fractions - because you can actually demonstrate that (simple ones, anyway) by saying if you have 40 cakes and you have to divide them all in half, how many half cakes do you have left at the end?
Obviously this becomes very unwieldy as the fractions get larger and more complex, but the demonstration of the maths is nice, and can then be applied to other examples (without cake).

67 using BODMAS rule

@YouMadeABear has it.

Hi, @ThumbWitchesAbroad -

That is extremely depressing about the Microsoft software. I had thought of raising this as a possibility earlier but thought it too unlikely!

I like one half of your cake example very much. If the question were ‘how many piggy servings of half a cake do we have?’ it would be lovely. Generally though dividing in half is ambiguous at best and usually taken to mean division by two.

I just posted the question under an alias and the first answer was beautiful, to with servings of half a grapefruit.

Nope, you're both wrong.

All the symbols on the bottom row are subtly different than the ones that went before - you need to look more closely at them.

My very numerically able 9 year old says he makes it 67

Without me showing him the two choices

@Moonopoly -

He gets full marks for method, just like the OP. Like her he isn’t picking up on the differences on the clockface, the size of the banana bunch, the inscribed shapes. What we are to make of those is subjective but one answer does ‘feel’ best.

@shmithecat2 I am not sure. Many people insisting it was 20, some of my friends who are not stupid at all could not understand even after explaining it. The kids knew instantly but they are doing it regularly I guess.

Yes it could have been written as 40÷1/2 but still the same. I can understand misreading the calculation but people genuinely didn't understand even after explaining it.

It's 38 as others have said.
2 (o'clock) + 3(bananas) + 3(bananas) x 11 (sides on shapes)
2+3+33=38

You do not need to have brackets in place to use the bid as rule.

*bodmas

@ThumbWitchesAbroad I don't think have ever used the Microsoft calculator as work on excel, that is ridiculous though

@Mathsquery58 ah! I’ll get him to take another look

38, definitely