In this post we will understand how positive and negative integers are represented in the number line and how we can perform addition of two different integers.
In number line, positive and negative numbers are represented as follows:
a. Positive integers are written at the right of zero
b. Negative integers are written at the left of zero
Addition of integers takes three forms
1. When both integers are positive
2. When both integers are negative
3. When one integer is positive and other is negative
When both integers are positive integers–
1. Add 6 + 3
Steps-
- On the number line first move 6 steps to the right from 0.
- We reach at 6 then move 3 steps to the right of 6.
- Here we reach at 9.
Thus we get 6+3=9 (in diagram blue circle shows the answer)
2. Add 4 +7
Steps-
- On the number line first move 4 steps to the right from 0.
- We reach at 4 then move 7 steps to the right of 4.
- Here we reach at 11.
Thus we get 4 + 7= 11 (in diagram blue circle shows the answer)
3. Add 5 + 6
Steps-
- On the number line first move 5 steps to the right from 0.
- We reach at 5 then move 6 steps to the right of 5.
- Here we reach at 11.
Thus we get 5 + 5= 11 (in diagram blue circle shows the answer)
When both integers are negative integers
When both integers are negative, the final result is addition of number with negative sign
1. Add (-6) + (-3)
Steps-
- On the number line first move 6 steps to the left from 0
- We reach at -6 , then move 3 steps to the left of -6
- Here we reach at -9
- Thus we get -6+-3=-9
2. Add (-7) + (-5)
Steps-
- On the number line first move 7 steps to the left from 0
- We reach at -7 , then move 5 steps to the left of -7
- Here we reach at -12
- Thus we get (-7) + (-5) =-12
When one integer is positive and another is negative
1.Add -6 and 3
Steps-
- On the number line first move 6 steps to the left from 0
- We reach at -6, then move 3 steps to the right of -6
- Here we reach at-3
- Thus we get -6+3=-3 (in diagram red dot shows the answer)
Tip –> For subtraction move left in number line and for addition move right in number line.
2. Add (-7) + 8
Steps-
- On the number line first move 7 steps to the left from 0
- We reach at -7, then move 8 steps to the right of -7
- Here we reach at1
- Thus we get -7+8=1 (in diagram red dot shows the answer)