Objective:
At the end of the topic, readers or learners are expected to solve problems on subtraction of integers.
Review:
We use the integer line to solve some problems on addition of integers. Just to highlight 馃憞馃憞馃憞
- Positive numbers are located at the right.
- Negative numbers are located at the left.
- We always start from zero then the next movement will start from the end of the first movement we had.
Today we are going to move to our new topic which is the part 2 of operation integers the SUBTRACTION.
In subtraction we need to change the sign of subtrahend which is the second number and proceed to addition like this 馃憞馃憞
Example:
- 1- (-2)= +3
Why?
Following the rule we change the sign of the subtrahend which is -2 so it will become +2 and we will proceed to addition so rewriting it馃憞
1+(+2)=1+(+2)=+3
Looking at the movement trend at the line of integers. Since the both are positive, therefore they will move to the right.
Example 2:
-2-(+3)= -5
Why?
Again following the rule we change the sign of the subtrahend which is +3 it will become -3 and proceed to addition that is why we have -5.馃憞
-2+-3=-5
Note: in adding numbers with same sign just proceed to adding the too numbers and copy the common sign like in our example both are negative. So, 2+3 is 5 and both are negative, therefore are final answer is -5.
Looking at the trend of movement at our line of integers 馃憞馃憞馃憞
Both are negative so both move to the left. As a result we got -5.
Checkpoint:
- 2- (-2)=
- 3-(+3)=
- -5-(-6)=
- 6-(-6)=
- -17-(-6)=
I hope you learn something for today and i will know it if you answer the checkpoint.
Guys let me know also your strat by commenting below.
Thank you so much.