1. Using Counters
Objective: Use counters to solve the addition of negative and positive integers.

2. Adding positive integers
We already know that the addition of positive integers results in a like sign answer. 5

3. Adding positive integers
We already know that the addition of positive integers results in a like sign answer.
5 + +

4. Adding positive integers
We already know that the addition of positive integers results in a like sign answer.
5 + 4 +

5. Adding positive integers
We already know that the addition of positive integers results in a like sign answer.
5 + 4 = + =

6. Adding positive integers
We already know that the addition of positive integers results in a like sign answer.
5 + 4 = 9 +
= 9

7. Adding positive integers
We already know that the addition of positive integers results in a like sign answer. This can be applied to the addition of negative integers.
5 + 4 = 9 +
= 9

8. Adding positive integers
We already know that the addition of positive integers results in a like sign answer. This can be applied to the addition of negative integers. -5

9. Adding positive integers
We already know that the addition of positive integers results in a like sign answer. This can be applied to the addition of negative integers.
-5 + +

10. Adding positive integers
We already know that the addition of positive integers results in a like sign answer. This can be applied to the addition of negative integers.
-5 + (-4) +

11. Adding positive integers
We already know that the addition of positive integers results in a like sign answer. This can be applied to the addition of negative integers.
-5 + (-4) = + =

12. Adding positive integers
We already know that the addition of positive integers results in a like sign answer. This can be applied to the addition of negative integers.
-5 + (-4) = -9 + =

13. Adding integers with different signs
Rule: Subtract the absolute values of the integers. The difference will have the same sign of the integer with the greatest absolute value.

14. Example
Find –4 + 5
The absolute value of negative four is four. The absolute value of positive five is five. The difference of their absolute values is one. The largest absolute value is five so the answer “one” get the sign of the five which is positive.
So, = +1

15. Alternative Method Use counters to add unlike signed integers.-4

16. Alternative Method Use counters to add unlike signed integers.
-4 + 5 +

17. Alternative Method Use counters to add unlike signed integers.
-4 + 5
A positive and a negative together become neutral. When we put a negative with a positive, they go away. +

18. Alternative Method Use counters to add unlike signed integers.
-4 + 5
A positive and a negative together become neutral. When we put a negative with a positive, they go away. +

19. Alternative Method Use counters to add unlike signed integers.
-4 + 5
A positive and a negative together become neutral. When we put a negative with a positive, they go away. +

20. Alternative Method Use counters to add unlike signed integers.
-4 + 5
A positive and a negative together become neutral. When we put a negative with a positive, they go away. +

21. Alternative Method Use counters to add unlike signed integers.
-4 + 5
A positive and a negative together become neutral. When we put a negative with a positive, they go away. +

22. Alternative Method Use counters to add unlike signed integers.
-4 + 5
A positive and a negative together become neutral. When we put a negative with a positive, they go away. +

23. Alternative Method Use counters to add unlike signed integers.
-4 + 5
A positive and a negative together become neutral. When we put a negative with a positive, they go away. +

24. Alternative Method Use counters to add unlike signed integers.
-4 + 5
A positive and a negative together become neutral. When we put a negative with a positive, they go away. +

25. Alternative Method Use counters to add unlike signed integers.
-4 + 5
A positive and a negative together become neutral. When we put a negative with a positive, they go away.
That leaves a positive one as our answer. It is the same answer that we got using strictly math. =