1tto check H9 negative numbers par 1-3

This lessonup is meant as a check of calculating with negative numbers 

If you walk to the right you add 

If you walk to the left you subtract (-)

If you add or subtract a postive number you walk forwards

If you add or subtract a negative number you walk backwards

Look at the picture on the right. 

If you add a number you turn your nose to the right

If you subtract a number you turn your nose to the left

If you add or subtract a positive number you walk forwards

If you add or subtract a negative number you walk backwards

If you walk to the right you add 

If you walk to the left you subtract (-)

If you add or subtract a postive number you walk forwards

If you add or subtract a negative number you walk backwards

Adding (walk to the right) a positive number  (walking forwards)

8 + 6 = 14 

If you walk to the right you add 

If you walk to the left you subtract (-)

If you add or subtract a postive number you walk forwards

If you add or subtract a negative number you walk backwards

Subtracting (nose to the left) a negative number (walk backwards).

If you stand at position 8 on the number line, nose to the left and you walk backwards 6 steps you end up at 14.

8 - -6 = 14 

We can see that both examples have the same answer:

8 + 6 = 14   and also

8 -  -6 = 14 

Conclusion: subtracting a negativen number is the same as adding a positive number !!!

By the way....

The brackets around -6 in the picture are not necessary (nodig) but are just to clarify that the negative minus belongs to the 6. In class we will not write these brackets

Now let's start practising...make the next exercises and fill in your answer. Important, if your answer is a negative number do not write a space in between the minus sign and the number. 

Now let's start practising with the next exercises. There is an automatic check if your answer is correct. This will only work if you do not write a space between a negative sign and the number. For example, if  your answer is minus 5 just typ -5 and not:  -  5 . Okay? :D

10 - 12

30 + -12

5 - 17 =

-8 - 14 =

-3 - 5 =

4 - -11=

-10 - -4 =

-20 - 8=

31 + -50

14 - -10=

8 + -9=

-7 - -7 =

How are you doing? Would you like more explanation and practising on this section or not?

I find it difficult and need more explanation/practising

I'm doing quite all right, I get it and I am ready to move on!

If your answer to the previous question was: I need more instruction, then your homework will be to make the support exercises: S10 and S13 on page 55 and S18, S21 and S23 on page 59.

If your answer was that you understood everything your homework will be the challenge exercises:  C3 and C4 on page 55 and C5 and C6 on page 59.