1TH/vwo §8.2, §8.3 and §8.4 once more.

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 1

Some more practice with §8.2, 3 and 4

Nothing new, this time.

This makes sense, as doing adding and subtracting with 

positive and negative numbers is quite tricky!

This lesson ...

+ you'll get a lotta time to work on with the SUMMARY/EXTRA EXERCISES

+ a Movie about adding and subtracting with positive and negative numbers

+ then follows a short look back at §9.2 and §9.3

Adding 1:

6 + 7 = 13

The simplest type of exercise.

A positive number, 7, is added to a number. This makes the result greater than the start:     13 is greater than 6.

Adding 2:

7 + -4 = 3

A NEGATIVE number is added to a number.

Now the result is less:  3 is less than 7.

Subtracting 1:

8 - 5 = 3

A Positive number is subtracted from a number.

the result is less:   3 is less than 8.

Beware of the last type, next slide!   

Subtracting 2:

6 - -5 = ....

This is the most exciting type!

If a negative number is subtracted, it has the same effect as adding a positive number: 6 - -5 = 6 + 5 = 11

Once more the whitch's cauldron:

6 - -5 = ....

Suppose the start temperature in the cauldron

is 6 degrees. Now she takes out 6 Cold Blocks.

then it gets warmer in the cauldron!

So taking out cold blocks does the same as putting in hot blocks.

So: 6 - -5 = 6 + 5 = 11

-5 --6 = ...

1. -1
2. 11
3. 1
4. -11

--6 -7 = ...

1. 13
2. 1
3. -1
4. -13

6 + -3 x -4 =

1. -12
2. 18
3. -6
4. -1

6 + -3 x -4 =...

6 + 12 = 18

Homework time:

Finish the homework now.

Also CHECK it with the SOLUTIONSBOOK

Make a few pics and send them in in GC

The homework is about:

+ §9.2 and §9.3, that we just discussed!

+ Do some more exercises about this content,

    before we go on with §9.4 Multiplication and division

homework time

Now ALL make, check and hand in:

p.76 E1 and E2 completely       

After this, make the following tasks:

+  HV1X:     p.51   S3  +  S6        p.55  S10  +  S13       p.59  S18  +  S21  +  S23 

+  G1X + A1X:    p.51  C1  +  C2     p.55  C3  +  C4     p.59  C5  +  C6