# 1TH/vwo §7.4 Adding and subtracting fractions

Fractions??!
Next slides show you some of those little fellas!

1 / 28
Slide 1: Slide
WiskundeMiddelbare schoolhavo, vwoLeerjaar 1

This lesson contains 28 slides, with interactive quizzes and text slides. Lesson duration is: 30 min

## Items in this lesson

Fractions??!
Next slides show you some of those little fellas!

#### Slide 1 -Slide

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

#### Slide 3 -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 4 -Slide

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

#### Slide 8 -Slide

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

#### Slide 9 -Slide

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 -Mind map

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

#### Slide 12 -Slide

After this example
it's time for a joke!

2. Work it out.
4352=
timer
1:00

43
52
- = ....

#### Slide 16 -Mind map

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 -Slide

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

3           and      6          ?

Next slide explains this.
65
43

#### Slide 19 -Slide

By the way, did you know dogs have their maths too?
Just watch!

#### Slide 21 -Slide

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

#### Slide 23 -Slide

FOTOVRAAG
2. Work it out and
3. Key in your whole CALCULATION plus ANSWER in the next slide.
timer
1:30

#### Slide 24 -Slide

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

Solution:

#### Slide 26 -Slide

35, on p.24 is a task, that .....
.... asks for some more attention and time from you!
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 -Slide

Homework time
Do §7.4 yourself now.
You may skip:   27, 28 and 29