Came across this puzzle for an 8 year old

[Natasha1]

TL;DR Summary: This should be a simple maths problem

Can anyone solve this as I can't. I found it in my son's school book which we cannot do. (see picture attached).

 

[Ibix]

If you're allowed to assume that two of a symbol is twice the value of one of it (so the first line is three candles plus two hats) then yes, it's a system of simultaneous equations. If not, no, it's not possible.

Even with that assumption that's quite a challenge for an eight year old. My son is fifteen and has just finished studying simultaneous equations, and I gather that three-variable equations like this one is an A-level (17-18 year old) topic. This page covers solving two variable equations and this one covers three variable equations like you have here.

 

[marcusl]

Mentor note: Post edited as it originally provided too much help.
Agreed that it is not an appropriate problem for an 8 year old. Here's how to solve it using elimination/substitution.
Call hats H, candles C and mugs M. Solve the three equations for these variables.
Now you can find their product in #4.

 

[PeroK]

If in doubt, trial and error. The first equation implies the candle is an even number.

 

[Ibix]

I'd say the simplest approach is to look at the second and third equations. The difference on the right hand sides is 2, the difference on the left hand sides should tell you something about hat and candle. With that, you should be able to get hat or candle from the first equation. At that point it should all unravel.

I agree that writing them as H, C abd M will make the algebra easier.

 

[phyzguy]

I bet there are some 8 year olds that could solve it. There is nothing wrong with a challenging problem that makes you think.

 

[mcastillo356]

Hi @Natasha1

It's linear algebra. Call $x$ to the doll, or candle (I don't know what represents), $y$ to the cap, and $z$ to the cup. It goes like this:

$$\begin{align*}
x+2y+2x&=52\\
z+2z+2x&=41\\
2z+z+2y&=43\\
\end{align*}$$

Greetings

 

[Math100]

Is this really a math problem for eight-year old students? How come I have doubts?

 

[Mark44]

Is this really a math problem for eight-year old students? How come I have doubts?

Yeah, me too.

 

[berkeman]

Is this really a math problem for eight-year old students? How come I have doubts?

Well, it turns out the OP has a history here at PF of posting undergraduate math problems (often with no effort shown). So you might be able to read between the lines...

 

[gmax137]

It looks to me like the kind of thing that pops up in Facebook or Instagram, posted by someone trying to get a lot of comments. At least this one has a definite answer, unlike the 6 + 2 x 4 ÷ 3 nonsense.

 

[bob012345]

TL;DR Summary: This should be a simple maths problem

Can anyone solve this as I can't. I found it in my son's school book which we cannot do. (see picture attached).

View attachment 355339

Please give the book reference so we can see it in context. Thanks.

 

[rcgldr]

Reminds me of the guy that was so proud he solved a puzzle in 2 hours when the box stated 3 to 5 years.

 

[Ibix]

Wow. And still no answer

Yes, because it's the homework help forum, not the homework solved for you forum. See point 8 here.

 

[jackjack2025]

Yes, because it's the homework help forum, not the homework solved for you forum. See point 8 here.

But I did not provide the solution. The solution is not the numbers, the solution is the process to get those numbers. I am a bit baffled by this forum tbh

Post removed.

 

[Muu9]

The trick is to notice that the cups only appear in threes, so you can cancel them by subtracting eq 3 from 2

 

[mcastillo356]

It's a pity that so many times vanishes the original poster. Furthermore, it is frustrating

 

[Muu9]

It's a pity that so many times vanishes the original poster. Furthermore, it is frustrating

Does physicsforums email you when someone replies to your thread by default?

 

[mcastillo356]

Of course

 

[DaveC426913]

In a million years I would not have guessed that was a hat. I thought it was some zillennial cartoon character with serious hip dysplasia.

(I mean I'm not just hit-and-run trolling the thread. I was working on an answer and realized I did not know how to describe the symbols - until I found @mcastillo356's labels.)

 

[gmax137]

In a million years I would not have guessed that was a hat.

took me a minute, too

 

[DaveC426913]

took me a minute, too

View attachment 359940

Well now you've sent me down a rabbithole abojut .webp format graphics.

I've only ever seen .webp in Google image searches and assumed it was some proprietary format designed to discourage copy-pasting from Google results. Imagine my surprise to discover - not only is it intended as a better-performing replacement for .jpg and .png - but it has been around for 15 years and is supported by all major browsers...

(Which raises the question: why has an informal poll of my marketing department turned up zero designers who have even the slightest passing familiarity with the format?)

 

[jackjack2025]

It isn't a hat

 

[gmax137]

Well now you've sent me down a rabbithole abojut .webp format graphics.

Well just to confuse matters further, I edited my post to replace the image with a jpeg version - minutes after I posted it. So you must have looked at it while I was editing it.

When I first looked at my post, the image wasn't showing. Instead, it had the "view attachment xxxxx" link. That's when I realized I had simply uploaded the image file copied from google. I normally open images in Paint, resize (to a smaller file size), then save as jpeg before posting. Somehow I skipped all that with this image when I created my post.

 

[DaveC426913]

It isn't a hat

Google's image search seems to think it is:

I mean, technically, it's a knitted, tasseled toque, but that's still a subset of 'hat'.

 

[jackjack2025]

:)

I was more surprised people were happy that the other image is a candle

 

[DaveC426913]

:)

I was more surprised people were happy that the other image is a candle

Yes, it is as likely a praying doll wearing balloony pantaloons. Hard to say.

 

[jackjack2025]

Meditating girl. Not a candle

 

[DaveC426913]

Meditating girl. Not a candle

Citation?

 

[bob012345]

It seems to me the student can solve this problem by direct substitution without knowing anything about solving systems of simultaneous equations. BTW, there was a period a few years back where hats like those were popular among teens.

 

[sbrothy]

Is this the new way of teaching math I've heard about that leaves the parents of millenials non-plussed?

I suspect this is one of it's proponents: Jill Neumayer DePiper.

I would like to say I'm not pointing fingers but if I'm not then I'm not really sure what I'm doing. I'm certainly not calling her competency in question! I'm nowhere that much into this subject. She just kind of popped up without much work on my behalf.

"Jill Neumayer DePiper is an expert in mathematics education and leads large-scale research studies and evaluation studies to broaden access to high-quality instruction. Her research focuses on changes in teacher knowledge and instructional practices that advance the quality and equity of mathematics instruction, particularly focused in middle grades mathematics."

---- Jill Neumayer DePiper

Wested

 

[mcastillo356]

No idea @sbrothy, but IMO, PF should not accept those who don't respect PF clear and easy rules, ie, statement of the question, attempt to solve, a little bit of LaTeX... In a single word : effort.

 

[sbrothy]

No no. I agree with that. That was more of an aside so to speak.