# 1TH/vwo §7.4 Adding and subtracting fractions

§7.4 Adding and subtracting fractions.
Fractions??!
Forgotten all about them?
Next slides show you some of those little fellas!

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Slide 1: Tekstslide
WiskundeMiddelbare schoolhavo, vwoLeerjaar 1

In deze les zitten 30 slides, met interactieve quizzen en tekstslides.

Lesduur is: 30 min

## Onderdelen in deze les

§7.4 Adding and subtracting fractions.
Fractions??!
Forgotten all about them?
Next slides show you some of those little fellas!

#### Slide 1 -Tekstslide

First get organised:
-  open your Notebook and
- put a pen and pencil on your table
- next slide shows you several fractions

#### Slide 3 -Tekstslide

A fraction has a ......   and a ....... see below!
The number above is called:   the numerator ( = teller). It tells us: HOW MANY?
The number below is called:    the denominator (= noemer). It tells us the
TOTAL of the numbers and it's also the NAME.
4 = numerator     and
5 = denominator
54

#### Slide 4 -Tekstslide

Finally don't forget to SIMPLIFY the answer, if possible!

#### Slide 8 -Tekstslide

However ..... is it always just a piece of cake?

#### Slide 9 -Tekstslide

Sometimes it is harder to add or subtract fractions!
That is when the ................ of the fractions are unequal!
Fill in the missing word.

#### Slide 10 -Woordweb

With 'common' denominators 'equal' denominators are meant!

#### Slide 12 -Tekstslide

After this example
it's time for a joke!

#### Slide 14 -Tekstslide

1. Copy this task in your Notebook and
2. Work it out.
3. Finally key in your answer in the next slide.
4352=
timer
1:00

43
52
- = ....

#### Slide 16 -Woordweb

explanation:
the new denominator becomes         4 x 5 = 20 !

-                     =                           -                            =

In the next slide we are going to SIMPLIFY.  Just watch!
43
52
2015
208
207

#### Slide 18 -Tekstslide

The previous subtraction was pretty simple, but .........
......  how to add or subtract fractions like:

3           and      6          ?

Next slide explains this.
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43

#### Slide 21 -Tekstslide

The following slide ...
as it deals with tricky fractions!
Unequal denominators and more
trouble...

#### Slide 23 -Tekstslide

A Task for you again!
FOTOVRAAG
1. Copy this task in your Notebook.
2. Work it out and
3. Key in your whole CALCULATION plus ANSWER in the next slide.
timer
1:30

#### Slide 24 -Tekstslide

5 2/3 + 7/11 = ..........

Solution:

#### Slide 26 -Tekstslide

35, on p.24 is a task, that .....
.... asks for some more attention and time from you!
1st.   Do not only write down the final answer,
but just like in the examples we did together:
WORK THEM OUT, as you've just seen and done!
Good luck.

#### Slide 27 -Tekstslide

The last remark is: 'take out the whole numbers'.
GOOD NEWS:
This is something you DON'T HAVE TO DO!
For example:           is just as good as  1

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#### Slide 28 -Tekstslide

Homework time
Do §7.4 yourself now.