[MATHS Qs HELP] How do I do this on a calculator?

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Saint of Killers
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Post[MATHS Qs HELP] How do I do this on a calculator?
by Saint of Killers » Fri Nov 06, 2020 9:09 am

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I'm lost as to where to begin.

If I do 1/3 I get 0.333[repeating]

5/12 I get 0.4166[repeating]

So... do I just add the 33 and 41 (42?) to the 24? Or is it something else entirely? All the questions before this gave me a whole number to work with at the start.

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Cuttooth
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Cuttooth » Fri Nov 06, 2020 9:16 am

It's asking you to find the least common denominator for the first two fractions then add them together.

The remaining percentage would be the 24 who chose beef.

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Super Dragon 64
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Super Dragon 64 » Fri Nov 06, 2020 9:18 am

If you do 1 minus 1/3 minus 5/12 you get the proportion of people who had beef. In a scientific calculator, this would look like:

1 - (1/3) - (5/12) = 0.25 (which is the same as 1/4 and 25%)

So the 24 guests who had beef are 1/4 of the total guests therefore all the guests (1.0 or 100%) is 24 x 4 which is 96 guests.

Last edited by Super Dragon 64 on Fri Nov 06, 2020 9:20 am, edited 1 time in total.
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sawyerpip
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by sawyerpip » Fri Nov 06, 2020 9:19 am

It's probably easier to work in fractions not decimals, so first you want to get them all with the same denominator.

1/3 is the same as 4/12, so that means

4/12 chose pasta
5/12 chose chicken
The remainder chose beef

The remainder must be 3/12 because the fractions would need to add up to 1 to account for 100% of guests.

3/12 is the same as 1/4, so one quarter of guests chose beef. If 24 guests are one quarter, then there must be 96 guests total (24 * 4).

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Hypes
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Hypes » Fri Nov 06, 2020 9:25 am

Yes this way

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satriales
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by satriales » Fri Nov 06, 2020 9:26 am

Don't need a calculator:

8/24 choose pasta
10/24 choose chicken

18/24 choose not beef, so 6/24 (1/4) choose beef.

There are 24 beef so total guests = 24 * 4 = 96.

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Saint of Killers
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Saint of Killers » Fri Nov 06, 2020 9:31 am

Cuttooth wrote:It's asking you to find the least common denominator for the first two fractions then add them together.

The remaining percentage would be the 24 who chose beef.


Super Dragon 64 wrote:If you do 1 minus 1/3 minus 5/12 you get the proportion of people who had beef. In a scientific calculator, this would look like:

1 - (1/3) - (5/12) = 0.25 (which is the same as 1/4 and 25%)

So the 24 guests who had beef are 1/4 of the total guests therefore all the guests (1.0 or 100%) is 24 x 4 which is 96 guests.


sawyerpip wrote:It's probably easier to work in fractions not decimals, so first you want to get them all with the same denominator.

1/3 is the same as 4/12, so that means

4/12 chose pasta
5/12 chose chicken
The remainder chose beef

The remainder must be 3/12 because the fractions would need to add up to 1 to account for 100% of guests.

3/12 is the same as 1/4, so one quarter of guests chose beef. If 24 guests are one quarter, then there must be 96 guests total (24 * 4).


Thank you for taking the time to explain. There's a similar follow up question so hopefully I'll now have a better idea of how to go about doing it.

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Saint of Killers
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Saint of Killers » Fri Nov 06, 2020 9:39 am

satriales wrote:Don't need a calculator:

8/24 choose pasta
10/24 choose chicken

18/24 choose not beef, so 6/24 (1/4) choose beef.

There are 24 beef so total guests = 24 * 4 = 96.


Only just spotted this. Ta!

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Victor Mildew
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Victor Mildew » Fri Nov 06, 2020 9:47 am

Im so strawberry floating thick with maths, I genuinely have to count on my fingers :dread:

Hexx wrote:Ad7 is older and balder than I thought.
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Zilnad
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Zilnad » Fri Nov 06, 2020 9:48 am

Not sure if the answer is 55378008 or 71077345?

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Victor Mildew
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Victor Mildew » Fri Nov 06, 2020 9:50 am

STOP THE COUNT!

Hexx wrote:Ad7 is older and balder than I thought.
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Saint of Killers
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Saint of Killers » Fri Nov 06, 2020 9:57 am

Victor Mildew wrote:Im so strawberry floating thick with maths, I genuinely have to count on my fingers :dread:


Whatever helps :lol: I do taps (on my head, or on the exercise book with a pen) to help me keep track of where I am in a count.

I'm just petrified of strawberry floating up thanks to my dad givng up trying to teach me when I was young. Thanks dad :slol: I'm glad he didn't try his hand at teachng me English or I'd have been seriously strawberry floated.

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Cuttooth
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Cuttooth » Fri Nov 06, 2020 9:59 am

The calculation in full:

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Memento Mori
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Memento Mori » Fri Nov 06, 2020 10:00 am

Algebra is how I did this. Call the number of guests x.

x/3 + 5x/12 + 24 = x
So making everything on the left side have a common denominator:

4x/12 + 5x/12 + 288/12 = x

Simplifying:

(9x +288)/12 = x

9x +288 =12x
288= 3x
96= x

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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Saint of Killers » Fri Nov 06, 2020 10:09 am

Cuttooth wrote:The calculation in full:

Image


Thank you again.

I wouldn't have even known how to begin doing that :lol: There are three calculator challenges on this homework. The first one (which I again didn't notice said a calculator was allowed) I managed to figure out on paper rarther easily as it had a number to work with at the start, but this one... I don't even know why I'm supposed to just *know* some of the facts I'm reading in here.

Memento Mori wrote:Algebra is how I did this. Call the number of guests x.

x/3 + 5x/12 + 24 = x
So making everything on the left side have a common denominator:

4x/12 + 5x/12 + 288/12 = x

Simplifying:

(9x +288)/12 = x

9x +288 =12x
288= 3x
96= x


...

:lol: Hopefully I'll understand this in my third year of doing GCSE maths.

I would seriously consider trading a limb to have a good grasp of maths. A shame I actually have to work at it.

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Return_of_the_STAR
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Return_of_the_STAR » Fri Nov 06, 2020 10:12 am

Is the correct answer none due to COVID-19 lockdown restrictions.

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Memento Mori
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Memento Mori » Fri Nov 06, 2020 10:19 am

Saint of Killers wrote:
Memento Mori wrote:Algebra is how I did this. Call the number of guests x.

x/3 + 5x/12 + 24 = x
So making everything on the left side have a common denominator:

4x/12 + 5x/12 + 288/12 = x

Simplifying:

(9x +288)/12 = x

9x +288 =12x
288= 3x
96= x


...

:lol: Hopefully I'll understand this in my third year of doing GCSE maths.

I would seriously consider trading a limb to have a good grasp of maths. A shame I actually have to work at it.

Algebra is something that when it clicks in your head, you'll never forget it.

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Saint of Killers
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Saint of Killers » Fri Nov 06, 2020 10:23 am

Memento Mori wrote:Algebra is something that when it clicks in your head, you'll never forget it.


God I hope so! The number of things in maths I think I have a understanding of only to come to them later and draw a blank is countless. But I'm getting there. Slowly.

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Cuttooth
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by Cuttooth » Fri Nov 06, 2020 10:24 am

The thing with maths is there are almost always multiple ways to approach a calculation as people here have already shown, so my advice is to find the general approaches that make the most sense to you and stick with them.

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OrangeRKN
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PostRe: [MATHS Qs HELP] How do I do this on a calculator?
by OrangeRKN » Fri Nov 06, 2020 10:36 am

Calling it a "calculator challenge" might actually be a little confusing, think of it more as a logic puzzle. You probably don't need a calculator to work it out, the reason it's allowed is because they want the question to test your logic and not your multiplication.

The trick to this kind of question is seeing what you can work out based on what you are told. You are told the fraction of people that chose two out of three meals, so you can work out the third fraction of people as whatever fraction is remaining.

An easier version of the question would be:

There is an amateur football match.

All of the fans present support either the home team or the away team.

7/10 of the fans support the home team.

30 fans support the away team.

How many fans are there in total?


If 7/10 support the home team, then 3/10 must support the away team. If 30 people are three tenths, then the total number of people is 100.

It's the same logic in your question, just with harder numbers.

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