1TTO 8.3 Decimal numbers PTI

8.3 Decimal numbers
You all know about decimal numbers.
It is similar to fractions, but now written with a point and not with a fraction symbol.
So:   0.5    instead of   
21
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Slide 1: Slide
mathematicsMiddelbare schoolhavo, vwoLeerjaar 1

This lesson contains 18 slides, with interactive quizzes and text slides.

time-iconLesson duration is: 30 min

Items in this lesson

8.3 Decimal numbers
You all know about decimal numbers.
It is similar to fractions, but now written with a point and not with a fraction symbol.
So:   0.5    instead of   
21

Slide 1 - Slide

The same 'order of operations' as you learnt applies now!
And you can take the
+ sum
+ difference
+ product and 
+ quotient  again!
+ above all the brackets 'rule' again, having top priority!

Slide 2 - Slide

Slide 3 - Slide

Slide 4 - Slide

6.6 - 4 x 1.5 =
A
6
B
3.9
C
-0.6
D
0.6

Slide 5 - Quiz

explanation:
First comes X  and only then we do  -,  so:

6.6 - 4 x 1.5 =
6.6 - 6 = 0.6

Slide 6 - Slide

Slide 7 - Slide

Slide 8 - Slide

5.6 x 0.01 = ....
A
5600
B
0.56
C
0.056
D
560

Slide 9 - Quiz

explanation:
multiplying by 0.01 is the same as taking 
of that number, or placing the decimal point 2 places to the right, so:
5.6 x 0.01 = 0.056
 
1001

Slide 10 - Slide

Finally a remark about exercise 28:
In 28 the calculations have become that complicated, that it is important to work them out in a few steps!
Look at the following example.

Slide 11 - Slide

This becomes pretty tricky, reason for us to work it out on paper like this:

Slide 12 - Slide

In the last task of this LessonUp...
+ work out your CALCULATION on paper
+ take a picture and 
+ send it in in this LessonUp
+ I am counting on all of you to show your work
and not just the ANSWER!

Slide 13 - Slide

4.2 + ( - 28) : 4 = ......
So send in a pic of your CALCULATION!
82

Slide 14 - Open question

Explanation:
4.2 + (      - 28) : 4 =
4.2 + (64 - 28) : 4 =
4.2 + 36 : 4 =
4.2 + 9 = 
13.2
82

Slide 15 - Slide


5.7 + ( - ) = .........
52
42

Slide 16 - Open question

Explanation:
5.7 + (        -           ) =
5.7 + (25 - 16) =
5.7 + 9 = 
14.7
52
42

Slide 17 - Slide

Homework time

Slide 18 - Slide