# 1TTO §8.4 Adding and subtracting fractions

§8.4 Adding and subtracting fractions.
Fractions??!
Forgotten all about them?
Next slide shows you some of those little fellas!
Just lean back and let yourself be informed.

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Slide 1: Slide
WiskundeMiddelbare schoolhavo, vwoLeerjaar 1

This lesson contains 24 slides, with interactive quizzes and text slides.

Lesson duration is: 30 min

## Items in this lesson

§8.4 Adding and subtracting fractions.
Fractions??!
Forgotten all about them?
Next slide shows you some of those little fellas!
Just lean back and let yourself be informed.

#### Slide 2 -Slide

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 3 -Slide

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

#### Slide 7 -Slide

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

#### Slide 8 -Slide

When is it a bit more work to add or subtract fractions?
What kinda fractions are at stake then?

#### Slide 9 -Mind map

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

3/4 - 2/5 = ....

#### Slide 13 -Mind map

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

-                     =                           -                            =
43
52
2015
208
207

#### Slide 15 -Slide

But .........
How to add or subtract fractions like:

3           and      6          ?

Next slide explains more.
65
43

#### Slide 17 -Slide

The following slide ...
Asks for your complete attention,
as it deals with tricky fraction facets!
Unequal denominators and more
trouble...

#### Slide 19 -Slide

Just think hard about this one!
How to do it?! Think about common denominators, of course.
What is the final outcome?
Maybe you'll get the turn to share your answer!

5 2/3 + 7/11 =

Homework time