1TH/vwo §7.1 From description to formula

What is due, this lesson?
+ Ch 7 is on the menu the coming lessons.

1 / 24
volgende
Slide 1: Tekstslide
WiskundeMiddelbare schoolhavo, vwoLeerjaar 1

In deze les zitten 24 slides, met interactieve quizzen en tekstslides.

time-iconLesduur is: 50 min

Onderdelen in deze les

What is due, this lesson?
+ Ch 7 is on the menu the coming lessons.

Slide 1 - Tekstslide

First....
an amazing nature event !

Slide 2 - Tekstslide

Slide 3 - Tekstslide

Slide 4 - Tekstslide

a. We read this text together.
b. Answer the question below in the next slide.

Slide 5 - Tekstslide

Roughly how far away is the thunderstorm?
A
2 km
B
2 + 2/3 km
C
2.5 km
D
3 km

Slide 6 - Quizvraag

Solution:
It takes the thunder 3 seconds to travel 1 km.
So if you hear the thunder after 8 seconds, then it is
8 : 3 = 2  2/3 km away. Or 2.7 km, rounded off.
However, because the question said 'roughly' (ongeveer) also
2.5 km is a good answer.

Slide 7 - Tekstslide

Slide 8 - Tekstslide

A rule in words about thunder and lightning is:
If you divide the time in seconds the thunder takes to reach you by 3, you get the distance in km.

Slide 9 - Tekstslide

This Rule in Words is changed into a Formula now:
We alredy have a RULE IN WORDS:
If you divide the time in seconds the thunder takes to reach you by 3, you get the distance in km. 
Now we make a FORMULA:
time in seconds : 3 = distance in km 

Slide 10 - Tekstslide

What does a Formula have, but a Rule in Words does not?

Slide 11 - Woordweb

Solution:
A Formula has arithmetic symbols like:
+           -              x      :      and      =  
What is described (=beschreven)  in a Rule in Words, is made into a Calculation in a Formula.

Slide 12 - Tekstslide

Slide 13 - Tekstslide

Slide 14 - Tekstslide

Let's make a Formula now!
In the next exercise you get some information.
You are asked 
A) to make a Formula and then 
B) to make a Calculation with it.
By the way: a Formula should be applicable (toepasbaar) for any number that you like to fill in.
For every number another outcome will follow.
A Formula does not have one fixed outcome!

Slide 15 - Tekstslide

START your Formula with:
Weight of a box =  .............................
Note: You can also END your Formula by it, so like this:
 ..................................... =  Weight of a box.

Slide 16 - Tekstslide

Formula .... ?

Slide 17 - Woordweb

The correct Formula is:

number of balls x 60 + 250 = weight,  or
250 + number of balls x 60 = weight,  or 
weight = number of balls x 60 + 250
So you see that there are more ways to write it down!

Slide 18 - Tekstslide

Slide 19 - Tekstslide

Now answer this one, using the Formula you just made!

Slide 20 - Tekstslide

Calculate the weight of a box containing 6 balls.
The Formula is:
number of balls x 60 + 250 = weight
A
600
B
590
C
580
D
610

Slide 21 - Quizvraag

Solution:

Slide 22 - Tekstslide

Summarising:
Sometimes you have a Description or a Formula in Words (that's the same).
You can change this into a Formula.
In a Formula you can fill in a given number, to get an outcome.
Like we just did.

Slide 23 - Tekstslide

Homework time
Time to do §7.1 now.
You may skip 6, as we just did this one.
Don't forget to 
+ check with the Solutionsbook    +    take pics and
+ send it in in GC. 

Slide 24 - Tekstslide