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1TH/Vwo §8.5 multiplying fractions

§8.5 Multiplying fractions
After   +       and        -     we now look at
the operation:       x   !
By the way, this is a pretty long LessonUp.
The Homework however is only 3 exercises.

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Slide 1: Tekstslide
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In deze les zitten 34 slides, met interactieve quizzen en tekstslides.

time-iconLesduur is: 30 min

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§8.5 Multiplying fractions
After   +       and        -     we now look at
the operation:       x   !
By the way, this is a pretty long LessonUp.
The Homework however is only 3 exercises.

Slide 1 - Tekstslide

First we multiply a fraction by a whole number:

Slide 2 - Tekstslide

Slide 3 - Tekstslide

Now it's your turn:

Slide 4 - Tekstslide

32
timer
1:00
x 33 = ...

Slide 5 - Woordweb

solution:

Slide 6 - Tekstslide

another one for you:

Slide 7 - Tekstslide

3/13 x 52 = ....
timer
0:25
A
10
B
9
C
14
D
12

Slide 8 - Quizvraag

Solution:

Slide 9 - Tekstslide

Slide 10 - Tekstslide

Now let's talk business:
Finally it's
Fraction times Fraction ...

Slide 11 - Tekstslide

Slide 12 - Tekstslide

2 Important points:
.                        and               .


Slide 13 - Tekstslide

an even more important point is this:
 COMMON MISUNDERSTANDING; somebody tries to tackle the task below :
 ' Wait a sec, the new denominator is 14 x 4, but then it's still a long way....
              
                x            =         x          =                          x                         ??? I am at a loss...'
1413
43
5652
5642
.............
...............

Slide 14 - Tekstslide

Why does this method really suck?

Slide 15 - Woordweb

SOLUTION:

  When multiplying fractions with unequal denominators,
    you don't have to make them equal!!
Watch the next slides that show how simple it really is!

Slide 16 - Tekstslide

Slide 17 - Tekstslide

Slide 18 - Tekstslide

Slide 19 - Tekstslide

Slide 20 - Tekstslide

your turn again:

Slide 21 - Tekstslide

3/8 x 3/8 = ...
timer
0:25
A
9/8
B
9/64
C
6/16
D
3/64

Slide 22 - Quizvraag

Solution:

Slide 23 - Tekstslide

Fotovraag: first work it out in your Notebook, take a pic and send in in next slide!
 Show your CALCULATION!





Don't forget to SIMPLIFY your answer, in the end!

Slide 24 - Tekstslide

2/7 + 1/7 x 1/2 = ......
timer
1:00

Slide 25 - Open vraag

Solution:

Slide 26 - Tekstslide

Now it's time for a complicated one:




Think about HOW to WORK it out!
 After that we look at the solution.

Slide 27 - Tekstslide

This is the Solution:

Slide 28 - Tekstslide



For example this one.                                   You might think:
2  x  3 = 6      and                 x          = 

So the final answer is:        6   +        =   6                 However this is WRONG!

21
41
81
81
81

Slide 29 - Tekstslide





Let's look back at the previous slide for a sec to see if both methods are good!

Slide 30 - Tekstslide

Fotovraag:
again work it out in your Notebook first and then send it in.

Slide 31 - Tekstslide

1 1/8 x 1 1/3 = ......
timer
1:30

Slide 32 - Open vraag

Solution:

Slide 33 - Tekstslide

Homework:
§8.5 Make only these tasks:
40, 42, 44 and 45. (you've done so much already!)
Send in your CALCULATIONS.
NOTE:  Showing only the answers has no value.
It's about WRITING DOWN the process in LITTLE STEPS!

Slide 34 - Tekstslide