1TTO §8.2 Adding negative numbers 24-25 PTI

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

8.2 We're going to do some adding ...

with Positive and especially Negative Numbers!

As usual...

this LessonUp marches through the most

important aspects of the whole paragraph,

making it much easier to deal with it yourself, afterwards!

We're gonna do several exercises together, so: less homework.

A cauldron (ketel) 

+ she puts in HOT BLOCKS and also

+ COLD BLOCKS 

+ to control the temperature

+ (every Block represents one degree!)

+ if there are just as many Hot blocks as there are Cold Blocks,

+ then the temperature is 0 degrees.

The temperature is 0 degrees.
If added 5 cold blocks. (1 block = 1 degree)
What's the new temperature?

1. 5
2. +5
3. -5

There are 13 cold blocks and 7 hot blocks in the cauldron.
What is the temperature?

1. -6
2. 6
3. 20
4. -20

Explanation:

13 cold blocks correspond to -13 degrees

7 hot blocks correspond to +7 degrees,

so the calculation is:

-13 + 7 = -6

In the next slide...

+ many changes in temperature come up!

+ your teacher will tackle the first line

+ then all think about the next line

+ one of you will get the turn!

+ and so on with the 3rd line, etcetera

Exercise 9

Finally:

        An example of this follows!

Draw a numberline and find the missing number

Now think about this one for a while!

                               Next slide will provide us with the Solution!

Using the number line, you that you have to

add up the length from 13        till 0,

and the length from 0 to -2.5 !

That is:   13       +   2         =     15 

However we go from positief to negative,

so we subtract. The answer is:  -15.9

​5​​2​​

​5​​2​​

​10​​5​​

​10​​9​​

Homework time

Evaluation