Function Machines

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breward
Posts: 9
Joined: Sun Feb 05, 2012 11:21 am

Function Machines

Post by breward »

Stuck on homework...

David transports bikes to Manchester. He calculates transport costs per bike as the cost of fuel and a driver divided by the number of bikes. For the journey he pays £150 to the driver and £200 for the fuel.

Draw a function machine to work out the cost of transport per bike.


We can't work out what you input. We know the answer but not how you get there!
yoyo123
Posts: 8099
Joined: Mon Jun 18, 2007 3:32 pm
Location: East Kent

Re: Function Machines

Post by yoyo123 »

costs as input , function machine divided by number of bikes, output cost per bike?

Seems too simple though
breward
Posts: 9
Joined: Sun Feb 05, 2012 11:21 am

Re: Function Machines

Post by breward »

Thanks for your reply. It does seem too simple and we are still confused with input x and output y.

If the number of bikes transported is 100. The cost (output y will be £3.50)

Can you have a function machine where the x value is in the middle, rather than inputted?

So 150 ---> +200 ----> divided by x ----> y
yoyo123
Posts: 8099
Joined: Mon Jun 18, 2007 3:32 pm
Location: East Kent

Re: Function Machines

Post by yoyo123 »

function machines can be 2 step, but the input is fixed as 150 and 200 isn't it?

The point if function machines ( as far as I can see!) is that you can alter input , do the "function" and then get an output.

Seems weird that it is a fixed input too. What year group is this aimed at?
southbucks3
Posts: 3579
Joined: Tue Dec 18, 2012 11:59 am

Re: Function Machines

Post by southbucks3 »

I can only think a function machine will allow his costs to fluctuate, as in real life..petrol going up in price, but his lorry always holds the same number of bikes regardless.
yoyo123
Posts: 8099
Joined: Mon Jun 18, 2007 3:32 pm
Location: East Kent

Re: Function Machines

Post by yoyo123 »

Function machines are pretty basic though, used in KS1.

eg.

Input -------> Function..........................> Output

X +3 Y

2 5
4 7
breward
Posts: 9
Joined: Sun Feb 05, 2012 11:21 am

Re: Function Machines

Post by breward »

Yippee! We've worked it out...

Input x ---> 1/x ----> times £350 ----> output y

So if x=100 bikes, y= £3.50 ... if x=200, y=£1.75 etc

Homework for Y7 GS.

Luckily the rest of the homework is very straight forward. :)
yoyo123
Posts: 8099
Joined: Mon Jun 18, 2007 3:32 pm
Location: East Kent

Re: Function Machines

Post by yoyo123 »

well done!


I like to think I played my part, if only by muddying the waters ,so that you could think strategically....it is my strong point!
Proud_Dad
Posts: 500
Joined: Fri Oct 11, 2013 9:55 am

Re: Function Machines

Post by Proud_Dad »

The input is the number of bikes. The costs are fixed values. The output is the cost per bike.
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