Help with a math problem please.

[Aintnosunshinewhenimgone]

Dd has a problem in her math book and we are struggling to answer it- there is no answer in the book. The question is: can you make a system of 3 coins that would allow you to make every number from 1-50 if you only had one of each coin?? Ypu can make up your own coins e.g. 3p 15p etc but can only use each one once to make each number. I'm stuck and stubborn so someone please help!! Thank you

Yes, with 6 coins. The amounts are:
1,2,4,8,16,32.

In that case @peakotter has given you the solution.

1,2,4,8,16,32...you’re effectively counting in binary!

1
2
2,1
4
4,1
4,2
4,2,1
8...

Damn cross post

It a totally batshit idiotic question. Said it back with a letter of complaint.

@00100001

You're missing the 's' on the end.

Problem solved.

Ha ha, yes!!

What?
So if you've used a 1p+2p+3p to make 6p, that's it,can't ever use 1 2 or 3 again??

Can you post the a actual question please?

Question has been answered
The irony of your username 😂

Yes, the problem is really just an introduction to binary arithmetic, isn’t it.

1p 2p 5p
1-1
2-2
3 - 1+2
4- 5-1
5-5
6- 5+1
7-5+2
8-5+2+1
9-5x2-1
10- 5x2
11-5 x 2 +1

I know technically you can't have two of the same coin, but if you are allowed any sign, plus brackets then maybe?

Apologies, I didnt refresh!

@TicTacTwo

Question has been answered The irony of your username 😂

Ha ha :p

Question still doesn't make sense.

Why aren't you allowed to use 1p ever again??

If you can't use the 1 again, how can you make the later numbers??

Or does she mean that you can't use the same coin twice in each sum??

As stated correctly above 1,2,4,8,16,32

Just like my imperial weights for by kitchen balance scales really. (1oz, 2oz, 4oz, 8oz, 1lb, 2lb)

Let me check I've got it first.

You have 6 coins and if you use any of them to make a number you can't use that value anymore?

Can you add more coins of different values in as the other get used?

This is going to totally bamboozzle the posters who only read the first post, how many more posts are we going to get saying it's impossible

I think pp have given you the answer and agree it is a tricky one! How old is DD?

I'm a primary school teacher and when I set a reasoning task like this, while I keep within within their realm of ability, my focus is not on whether they can find the answer but on developing other skills. I expect your daughter has demonstrated resilience, perseverance, some mathematical vocabulary, reasoning (I'll try this...but of that doesn't work then...well then I need to do this...next I can try...but if this, then that). All important skills too.

Six coins is a game changer, OP.

@ComeOnBabyHauntMyBubble

No, you can only use each coin once in making each number.

E.g. to make 3 you must use 1 + 2 not 1 + 1 +1
However when you make another number you get all 6 coins again. So 5 you can use the 1 again (4 + 1)

[quote August20]@ComeOnBabyHauntMyBubble

No, you can only use each coin once in making each number.

E.g. to make 3 you must use 1 + 2 not 1 + 1 +1
However when you make another number you get all 6 coins again. So 5 you can use the 1 again (4 + 1)[/quote]
That's what I thought, but OP's clarifications seemed to suggest otherwise. I'm even more confused.

How can you make 1 from 3 coins?

By using just a 1p coin?

I presumed you had to use all 3 coins - that was the least of the problems!

@ComeOnBabyHauntMyBubble

I think that's still right, when OP says "cant use 1p and 1p again" I believe she means you can't use 1 + 1 in the same question.

But you can use 1p again to make up a different number. The wording is just a little confusing.

The answer is "No".

@TeenPlusTwenties

As stated correctly above 1,2,4,8,16,32

Just like my imperial weights for by kitchen balance scales really. (1oz, 2oz, 4oz, 8oz, 1lb, 2lb)

Woah, mic drop moment... I never realised that imperial measures were effectively binary. I use my imperial balance scales all the time. I can't believe I never noticed! Mind is blown.

Mameha I have two sets of weights, imperial & metric.

The Imperial ones stack so beautifully on top of each other.
The metric ones drive me crazy as I have 2x20g and 2x200g weights so they don't stack properly at all.
This is one of the main reasons I use imperial if the cookery book gives both options.