# 1TH/Vwo §8.2 Powers

Now comes a powerful paragraph!
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Slide 1: Tekstslide
WiskundeMiddelbare schoolhavo, vwoLeerjaar 1

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

Lesduur is: 30 min

## Onderdelen in deze les

Now comes a powerful paragraph!

#### Slide 1 -Tekstslide

§8.2 Powers
Homework:  14  t/m  19

#### Slide 2 -Tekstslide

Here is a table with Length = 2 m  and also Width = 2 m.
The Area (=oppervlakte) = 2 x 2 = 4
Multiplying a number by itself -in this case 2- is called:
SQUARING a number.
The result is the SQUARE of a number. Let's look at a few more examples!
m2

#### Slide 3 -Tekstslide

'squaring' in dutch we call:

#### Slide 4 -Tekstslide

In the next slide
give the answers to these 5 exercises.

#### Slide 5 -Tekstslide

The 5 answers to the SQUARES are:
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A
1, 2, 3, 4 and 5
B
1, 4, 9, 16 and 25
C
2, 4, 6, 8 and 10

#### Slide 6 -Quizvraag

Solutions:
So, for example:
the SQUARE of 5 is
5 x 5 = 25.

#### Slide 7 -Tekstslide

However ...
sometimes you want to multiply a number by itself more than once. Then we can use a similar Notation as for the Square:
+  For example:  3 x 3 x 3 x 3 =
+  See the next slide for more! New examples and the new Words that come with this.
+  Like the word: POWER.
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#### Slide 11 -Tekstslide

is the same as ........
43
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A
4 x 4 x 4
B
4 + 4 +4
C
4 x 3
D
64

#### Slide 12 -Quizvraag

Explanation:
means the same as:
4 x 4 x 4,
but it also means: 64, because that is the outcome.
It doesn't mean 4 + 4 + 4, which you could write as 3 x 4 = 12.
Once more:                      = 4 x 4 x 4 = 64
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43

#### Slide 13 -Tekstslide

is the same as .....
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timer
0:20
A
8
B
2 x 2 x 2 x 2
C
16
D
2 + 2 + 2 + 2

#### Slide 14 -Quizvraag

Explanation:
is the same as:
+   2 x 2 x 2 x 2 , because a power is a multiplication, that is repeated.
+   16, because that's the outcome.
+   however, it's not about adding, so not 2 + 2 + 2 +2.
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#### Slide 15 -Tekstslide

REMEMBER THIS? IT'S FROM §8.1!

HOWEVER, THE POWERS HAVE TO HAVE A PLACE IN THIS NOW!
SEE NEXT SLIDE.

#### Slide 16 -Tekstslide

Watch below: between the 'brackets' and the 'multiplying/dividing' the POWERS are placed!
So it comes 2nd in place.

#### Slide 17 -Tekstslide

You don't have to actually work it out.
Just think about the ORDER in which to work it all out!

#### Slide 18 -Tekstslide

Here is the Solution:
(Study it carefully, because you're going to make one yourself!)

#### Slide 19 -Tekstslide

FOTOVRAAG:
1. Work this one out on paper.
2. Take a pic and
3. Send it in in next slide!

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1:30

#### Slide 20 -Tekstslide

My work in a Photo:

#### Slide 21 -Open vraag

Solution:
The POWERS between the BRACKETS have to be worked out first!
Following the PRIORITY rules we get:
7 x ( 36 - 32) = 7 x 4 = 28
A common mistake would be:
7 x ( 12 - 10 ) = 7 x 2 = 14   In this case you've done 6 x 2 and 2 x 5 instead of
calculating POWERS!  Another common mistake:
=   36 - 25 = 7 x 11 = 77      because here '7' disappeared for a while!?
7x(6225)

#### Slide 22 -Tekstslide

As for 18, above, mind the remark :
'Calculate as in the example above' !
So don't just give the answers -they are in the Solutionsbook too- but show the process of Calculating!
So: show your calculation. It also helps to gain points in the next test!

#### Slide 23 -Tekstslide

Homework time.
+  Do §8.2 in the usual way, finally sending in pics of your corrected work.
+   You may skip:  11, 12 and 13, as we have done a lot
together!