1TH/Vwo §7.1 Calculating with numbers

A look back at the Practice test from Ch6 first!
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Slide 1: Tekstslide
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In deze les zitten 42 slides, met interactieve quizzen en tekstslides.

time-iconLesduur is: 30 min

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A look back at the Practice test from Ch6 first!

Slide 1 - Tekstslide

What many people did not pick up yet was:
CHECKING by two CALCULATIONS if the 
point of intersection that you read off REALLY is the p.o.i.!
Let's Study the following instruction slide together.

Slide 2 - Tekstslide

So for these two graphs we are going to 
- read off the p.o.i. which is (5, 3.5) and also
- check this by filling in 5 in both formulas and seeing IF
   the outcome is 3.5 both times!

Slide 3 - Tekstslide

Slide 4 - Tekstslide

§7.1 Calculating with numbers
Homework:  2, 4  t/m  10
Some new words will come up!
It's important to know their meaning.
That's what this LessonUp is useful for.

Slide 5 - Tekstslide

§7.1 Calculating with numbers
Homework:  3  t/m  8
learning goals:
- what is a sum, a difference, a product and a quotient ?
- how to do calculations IN THE RIGHT ORDER

Slide 6 - Tekstslide

The new words:
brackets           product       quotient
sum             difference                   

Slide 7 - Tekstslide

Try to TAKE IN the following information.
Later in this LessonUp there will be several questions about it!

Slide 8 - Tekstslide

You get the Sum when ...
adding up two (or more) numbers together,
 Like  35 + 12 = 47
In fact 'the sum' is our 'de som'!
Indeed, awe-sum!      

Slide 9 - Tekstslide

Difference:
When you subtract 2 numbers from each other, 
the result is the Difference.
For example:          45 - 16 = 29,  
so 29 is the Difference of 45 and 16.

Slide 10 - Tekstslide

Product:
Multiplying 2 (or more) numbers by each other,
gives us the Product of the numbers.
Like 23 x 3 = 69, 
so 69 is the Product of 23 and 3.

Slide 11 - Tekstslide

Quotient:
When you divide 2 numbers by each other, the result is called the Quotient of them.
For example:  14 : 7 = 2,  
so the Quotient of 14 and 7 is 2.

Slide 12 - Tekstslide

timer
0:45
Mention the most important 4 words from the previous slides.

Slide 13 - Woordweb

The Product of 15 and 3 is ......
timer
0:15
A
18
B
5
C
45
D
12

Slide 14 - Quizvraag

The Product of 15 and 3 ....
means the Multiplication of 15 and 3, so:
15 x 3 = 45

Slide 15 - Tekstslide

The Sum of 34 and 13 is .........
timer
0:20
A
21
B
21
C
57
D
47

Slide 16 - Quizvraag

The Sum of 34 and 13 is ...
47, because the Sum means Adding!

Slide 17 - Tekstslide

The quotient of 27 and 9 is ........

Slide 18 - Open vraag

What has to do most with arithmetic?
timer
0:20
A
Sam
B
Siem
C
Sum
D
Sem

Slide 19 - Quizvraag

Slide 20 - Tekstslide

Maybe you remember from your old school ..
that x  and  :  go before  +  and   -.
This is still true.
However, there can be exceptions...
See next slide!

Slide 21 - Tekstslide

Slide 22 - Tekstslide

Brackets are the New Things!

Slide 23 - Tekstslide

Brackets? There are several kind of brackets!
In dutch 'beugels' comes nearest.
Next slide shows you brackets for arithmetics.

Slide 24 - Tekstslide

Amazing stuff, down here:

Slide 25 - Tekstslide

Amazing stuff, down here:

So, thanks to the Brackets (=haakjes), the old Priority (=voorrang) is changed.
In the first calculation we do   2 x 5   first,
but because of those Brackets we first do:     8 + 2.

Slide 26 - Tekstslide

What is the result of:
(6 + 6) : 3 ?
timer
0:30
A
3
B
4
C
9
D
-5

Slide 27 - Quizvraag

Explanation:       (6 + 6) : 3 =
First work out the Brackets:
(6 + 6) : 3 = 12 : 3 =4              (Notice that the Brackets have gone in the 2nd step, as they have no meaning any more.)
That's why the good answer is 4!
FINALLY:  Try to understand the meaning of the next slide!

Slide 28 - Tekstslide

Slide 29 - Tekstslide

In the next slide the meaning is explained!

Slide 30 - Tekstslide

Slide 31 - Tekstslide

Slide 32 - Tekstslide

A correct notation is important.
In the next slide, find the mistake!

Slide 33 - Tekstslide

5 + 5 x 3 = 15 = 5 + 15 = 20
The outcome is good, but the way of writing it all down contains a mistake.
Think hard about this. Which step above is not good?
Some of you get the turn.
Next slide gives the answer.

Slide 34 - Tekstslide

5 + 5 x 3 = 15 = 5 + 15 = 20
The outcome is good, but the way of writing it all down contains a mistake.
The Mistake:    ' = 15 '
It suggests that 15 is equal to the final outcome, 20.
Why? Well, there are ' = ' signs between every step, so every step must be equal to any other step!

Slide 35 - Tekstslide

5 + 5 x 3 = 5 + 15 = 20
One more time the good answer, above.

Slide 36 - Tekstslide

Work out:
4 : 2 + 7 x 3 - 4 x 2 = .......
timer
0:40
A
31
B
2 = 2 + 21 = 23 - 8 = 15
C
2 + 21 - 8 = 15
D
15

Slide 37 - Quizvraag

Fotovraag:
1. Work this task out in your Notebook.
2. take a picture of this and
3. send it in in the next slide!
4. so show us your Calculation and
5. NOTA = not only the Answer!

Slide 38 - Tekstslide

Calculate 7 + 3 x 4 : 6 - 5 = .........
timer
1:00

Slide 39 - Open vraag

Solution:

Slide 40 - Tekstslide

Homework time
+ You may skip exercises  1 and 3.
+ Next slide tells more about exercises  7 and 8.

Slide 41 - Tekstslide

Homework time-additional remark:
Exercises 7 and 8:
NOT ONLY THE ANSWERS!
1.  Copy the task in your Notebook
2. Make a CALCULATION for every task, just like you see 
    in the two EXAMPLES on p.12, right above exercise 7.
timer
30:00

Slide 42 - Tekstslide