Maths homework showing working out

[Emochild]

xxx = 3024

I know the answer is

9x8x7x6=3024

But how the heck does dd show her working?

I thought it was a trial and error question but apparently not and her teacher has told her off previously for not showing working

-all numbers have to be less than 10

[PberryT]

Can she break down 3024 into prime factors using the tree?

3024= 3x3x2x2x2x2x3x7 and then the prime factors multiply to get the numbers in the sum. Eg 9 is 3x3

[OhYouBadBadKitten]

Does the xxx stand for the digits?
She can find the prime factors first of 3024 using something like a prime factor tree then arrange as needed.

[Emochild]

Sorry, that didn't display properly

?x?x?x?=3024

[OhYouBadBadKitten]

ok, once you have the prime factors then you just have to group them into 4 groups so that each multiple is 9 or less.

[Emochild]

So a cherry tree thingy?

[Emochild]

I'm so technical

[OhYouBadBadKitten]

in the morning, if no one else has done it I'll sketch it out and take a photo.

[Emochild]

Thank you

The way dd worked it out was...

'I know 3000 and 24 are both in the 6 times table so that's my first number
3024/6=504
I know 504 is in the 4 times table and the 8 times table
504/8=63
7x9=63

So the numbers must be 6x8x7x9'

Works but long winded and not mathematical enough apparently

[OhYouBadBadKitten]

Odd, I'd consider that mathematical enough - though she could have started with I know that 3024 is divisible by 6 because it is an even number and the digits add to a multiple of 3.

[OhYouBadBadKitten]

here is how I'd do it.

[Emochild]

Thank you

No doubt I shall be back next week for more help

[OhYouBadBadKitten]

[MooPointCowsOpinion]

Her working out is fine to show how she did it, I'd be happy with that.

What did she do wrong before?

The only thing I can think perhaps she was specifically told to relate it to the topic of prime factor decomposition.

[Emochild]

Nope

No instructions other than what are the numbers

The same homework included compound interest and fractions with negative exponents

So a fun time was had all round!

[Emochild]

She was previously told off for not showing her working when the question was

3 to the power of 25= ?

The teacher made her write

3x3x3x3x3...............

[MooPointCowsOpinion]

25 3s! Screw that for a laugh!

Mine might write 3 x 3 x 3 ..... X 3 with a small indication that the ... Means a total of 25 times.

That teacher really likes people showing their working.

[Emochild]

Which is ironic because she gives questions like....

Give the value of (8/27)^-2/3

With no worked examples in their book or a text book to refer to!

[cdtaylornats]

3+0+2+4 = 9 so 3024 is divisible by 9


325 = 3535353535 = 243^5 = 847288609443

[MooPointCowsOpinion]

Emochild that's a grade A indices question.

Has to be done in 3 parts, I'd do 1/3 first (cube root) then 2 then ^-1 (flips the fraction) to get 9/4.

[Emochild]

Thanks moo and OYBK

I'm guessing you are both maths teachers?

I'm toying with speaking to the school about it but they've recently removed the ability to contact specific departments -you have to email the info@school email and hope it gets through to the right person

Also don't want to piss the teacher off so she takes it out on dd