# 1TH/Vwo §7.1 Calculating with numbers

A look back at the Practice test from Ch6 first!
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Slide 1: Slide
WiskundeMiddelbare schoolhavo, vwoLeerjaar 1

This lesson contains 42 slides, with interactive quizzes and text slides.

Lesson duration is: 30 min

## Items in this lesson

A look back at the Practice test from Ch6 first!

#### Slide 1 -Slide

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 -Slide

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 4 -Slide

§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 -Slide

§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 -Slide

The new words:
brackets           product       quotient
sum             difference

#### Slide 7 -Slide

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

#### Slide 8 -Slide

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 -Slide

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 -Slide

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 -Slide

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 -Slide

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

#### Slide 13 -Mind map

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

#### Slide 14 -Quiz

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

#### Slide 15 -Slide

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

#### Slide 16 -Quiz

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

#### Slide 17 -Slide

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

#### Slide 18 -Open question

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

#### Slide 20 -Slide

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 22 -Slide

Brackets are the New Things!

#### Slide 23 -Slide

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

#### Slide 24 -Slide

Amazing stuff, down here:

#### Slide 25 -Slide

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 -Slide

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

#### Slide 27 -Quiz

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 29 -Slide

In the next slide the meaning is explained!

#### Slide 32 -Slide

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

#### Slide 33 -Slide

5 + 5 x 3 = 15 = 5 + 15 = 20
The outcome is good, but the way of writing it all down contains a mistake.
Some of you get the turn.

#### Slide 34 -Slide

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 -Slide

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

#### Slide 36 -Slide

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 -Quiz

Fotovraag:
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 -Slide

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

Solution:

#### Slide 40 -Slide

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

#### Slide 41 -Slide

Exercises 7 and 8:
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