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: Tekstslide

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

Lesduur is: 30 min

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§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 1 - Tekstslide

Slide 2 - 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

\frac{​ 4 ​ ​}{​ 5 ​}

Slide 3 - Tekstslide

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

Slide 4 - Tekstslide

Slide 5 - Tekstslide

Slide 6 - Tekstslide

Slide 7 - Tekstslide

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

Slide 8 - Tekstslide

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

Slide 9 - Woordweb

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

Slide 10 - Tekstslide

Slide 11 - Tekstslide

Slide 12 - Tekstslide

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

Slide 13 - Woordweb

explanation:

the new denominator becomes 4 x 5 = 20 now!

- = - =

\frac{​ 3 ​ ​}{​ 4 ​}

\frac{​ 2 ​ ​}{​ 5 ​}

\frac{​ 1 5 ​ ​}{​ 2 0 ​}

\frac{​ 8 ​ ​}{​ 2 0 ​}

\frac{​ 7 ​ ​}{​ 2 0 ​}

Slide 14 - Tekstslide

Slide 15 - Tekstslide

But .........

How to add or subtract fractions like:

3 and 6 ?

Next slide explains more.

\frac{​ 5 ​ ​}{​ 6 ​}

\frac{​ 3 ​ ​}{​ 4 ​}

Slide 16 - Tekstslide

Slide 17 - Tekstslide

The following slide ...

Asks for your complete attention,

as it deals with tricky fraction facets!

Unequal denominators and more

trouble...

Slide 18 - Tekstslide

Slide 19 - Tekstslide

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!

Slide 20 - Tekstslide

Slide 21 - Tekstslide

5 2/3 + 7/11 =

Slide 22 - Woordweb

Homework time

Slide 23 - Tekstslide

Slide 24 - Tekstslide