NZ Level 5
topic badge
Functions Machines
Lesson

Making sausages

If you think of a sausage machine: something goes in, the machine works its magic, and sausages come out the other end! A function machine is a little like that, just with no sausages. We have 3 important things that happen though, just like a sausage machine.

Function machines

With a function machine, we have:

  • something going in (input)
  • something happening in the machine (operation)
  • something coming out (output)

Is that all?

Yes! It looks just like this. 

Let's watch a video to see how it works and how it can go in reverse as well.

 

Remember!

A function machine uses three special terms:

  • input
  • operation
  • output (We don't call this the answer)

Worked Examples

Question 1

Look at this function machine.

         
$2$2

$+$+$1$1

?
         
  1. In the case above, what is the output of the function machine?

  2. If the input was changed to $7$7, what would the new output of the function machine be?

Question 2

Look at this function machine.

         
$5$5

?

$7$7
         
  1. What is the operation of this function machine?

    $2$2

    A

    $7$7

    B

    $+$+$5$5

    C

    $+$+$2$2

    D

    $-$$2$2

    E

    $\times$×$2$2

    F

    $2$2

    A

    $7$7

    B

    $+$+$5$5

    C

    $+$+$2$2

    D

    $-$$2$2

    E

    $\times$×$2$2

    F
  2. We can reverse the direction of a function machine.

    $5$5

    ?

    $7$7

    Now $7$7 is the input and $5$5 is the output.

    What is the operation of this function machine now?

    $\times$×$2$2

    A

    $-$$2$2

    B

    $5$5

    C

    $2$2

    D

    $+$+$2$2

    E

    $-$$7$7

    F

    $\times$×$2$2

    A

    $-$$2$2

    B

    $5$5

    C

    $2$2

    D

    $+$+$2$2

    E

    $-$$7$7

    F

Question 3

Look at this function machine.

         
?

$+$+$5$5

$12$12
         
  1. In the case above, what is the input of the function machine?

  2. If the output was changed to $11$11, what would the new input of this function machine be?

What is Mathspace

About Mathspace