1TH/Vwo §3.4 Plotting graphs

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 1

§3.4 Plotting graphs

You're going to plot a lot of graphs today!

Finally you will exchange your Notebooks and give points for your neighbour's work.

an interesting exercise ...

                  we will do together right now!

+ take before you:  

      a.  Notebook

      b.   pen

      c.   pencil   and

      d.   geo triangle (or ruler), from your bag and pencil case!

Schermafbeelding 2020-10-12 om 13.27.34

Schermafbeelding 2020-10-12 om 13.27.55

 DRAW the HORIZONTAL axis.     

USE A PENCIL and a PENCIL ONLY !!!   (the numbers and words may be written with a pen)

Look at the lowest age in the table:  it is 6 years.

So: start your horizontal axis at 6 years!  See next slide.

However: 

               keep 10 cm open for the VERTICAL axis!

22a Above you see how the HORIZONTAL axis is drawn.

Once more: make sure you have about 10 cm for the VERTICAL axis!

Think it over and compare with your neighbour.

Answer 22b:

10 cm (or grids)  =    put 1 finger up

8 cm  =  put 2 fingers up

12 cm  = put 3 fingers up

22b

8 cm (or grids) is the right answer, 

because 20 cm is the smallest length and

 58 cm is the greatest length.

    We use numbers like 20, 25, 30  etcetera.

 60 cm is nearest to 58 cm.

Then we need at least:        60 - 20 = 40,           40 : 5 = 8 grids.

Let me be honest.....

The answer, given in the previous slide,

was not quite accurate...

In fact you need (at least) 9 cm and not 8 cm.

The cm extra is for a ZIGZAG, that covers     0 cm  -    20 cm ! 

Now we do question 22c!

like the river in the previous slide .....

our activities keep flowing !

Just go with the flow!

S

Answer to 22c:

If you think:

variable= kg     and    unit =   weight,    then   raise 2 fingers

variable = weight   and   unit = kg,            then  raise 4 fingers.

Answer and Explanation 22c:

variable = weight

and       unit = kg    (eenheid),

so 4 FINGERS was correct!

A variable (something that changes over time, in this case weight) 

is expressed in a unit (in this case kg)!

     So go ahead and draw. Don't forget the ZIGZAG for 0 - 20 kg!

In the next slide ....

+ you see the complete graph already

+ but for now it's only about the axes! 

Now do tasks e and f!

Rounding off this exercise ...

+  Look critically at your neighbour's graph:

+ is it correct and neat (no crossing out)?  = 1 point

+ did (s)he use a pencil?                                        = 1 point

+ are the axis drawn as straight lines?           = 1 point

+ totalise the points and give back the Notebook

+ if you scored at least 2 points, then the coming JOKE is for you!

Abov

Above the general way to make a GRAPH from a TABLE is shown!

Next slide gives an example.

TASK:

In the GRAPH in the following slide

there is something NEW.            I've got 2 questions about it:

1st What's new?! 

 2nd What's the great thing you can READ OFF now?

Discuss this with your neighbour!

Answer:

1st   Two graphs are shown.

2nd  The great thing about this is that you can

COMPARE (vergelijken) them!!     

Homework time

Do:

§3.4 Plotting graphs, you may SKIP 22.

Havo and H/V:    choose from support and Standard paths.

Vwo: Why not trying the Challenge path?!