1. Addition and Subtraction of
Integers
In this tutorial, we will learn how to add and subtract
signed numbers with the help of a toy car.
The line the car sitting on is called the number line,
where the positive numbers are on the right and the
negative numbers are on the left.
2. Addition and Subtraction of
Integers
The car will stick to the following rules:
1. It always starts at 0 (its home) facing right.
2. If it sees a positive number, it moves forward.
3. If it sees a negative number, it backs up.
4. If it sees an addition sign, it continues to read the next
number.
5. If it sees a subtraction sign, it turns around and then
continues to read the next number.
Click to see the first example.
3. Example 1: 2 + 4
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right
(click to see animation)
4. Example 1: 2 + 4
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right
5. Example 1: 2 + 4
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right
6. Example 1: 2 + 4
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
7. Example 1: 2 + 4
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.3. Next the car will move 4 more
units forward because it sees the
number 4.
(click to see next animation.)
8. Example 1: 2 + 4
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.3. Next the car will move 4 more
units forward because it sees the
number 4.
(click to see next animation.)
9. Example 1: 2 + 4
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.3. Next the car will move 4 more
units forward because it sees the
number 4.
Since the car now stops at 6, the
answer to 2 + 4 is 6.
(click to see the next example)
10. Example 2: (-2) + 5
1. Our car starts from 0 facing
right.
2. It then backs up 2 units (to the
left) because it sees the - sign.
(Click to see animation)
11. Example 2: (-2) + 5
1. Our car starts from 0 facing
right.
2. It then backs up 2 units (to the
left) because it sees the - sign.
12. Example 2: (-2) + 5
1. Our car starts from 0 facing
right.
2. It then backs up 2 units (to the
left) because it sees the - sign.
13. Example 2: (-2) + 5
1. Our car starts from 0 facing
right.
2. It then backs up 2 units (to the
left) because it sees the - sign.
3. Next it will move forward by 5
units.
(click to see animation)
14. Example 2: (-2) + 5
1. Our car starts from 0 facing
right.
2. It then backs up 2 units (to the
left) because it sees the - sign.
3. Next it will move forward by 5
units.
15. Example 2: (-2) + 5
1. Our car starts from 0 facing
right.
2. It then backs up 2 units (to the
left) because it sees the - sign.
3. Next it will move forward by 5
units.
16. Example 2: (-2) + 5
1. Our car starts from 0 facing
right.
2. It then backs up 2 units (to the
left) because it sees the - sign.
3. Next it will move forward by 5
units.
Now it stops at +3, therefore the
answer to (-2) + 5 is 3.
Please go to the next tutorial for subtractions.
17. Subtraction
1. There is a big difference between
addition and subtraction.
2. In addition, our car is always
facing right, because that is the
positive direction,
3. but in subtraction, the car has to
turn around (180 deg) first.
Click when you are ready.
18. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
(Click to start animation)
19. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
20. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
21. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
22. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
3. Next it will turn around because it
sees the subtraction symbol – .
Click to see animation.
23. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
3. Next it will turn around because it
sees the subtraction symbol – .
24. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
3. Next it will turn around because it
sees the subtraction symbol – .
25. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
3. Next it will turn around because it
sees the subtraction symbol – .
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
3. Next it will turn around because it
sees the subtraction symbol – .
4. Finally it will move forward (to
the left) by 3 units.
click to see animation.
26. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
3. Next it will turn around because it
sees the subtraction symbol – .
4. Finally it will move forward (to
the left) by 3 units.
27. Example 3: 5 – 3
1. Our car still starts at 0 facing
right.
2. It then moves forward 5 units.
3. Next it will turn around because it
sees the subtraction symbol – .
4. Finally it will move forward (to
the left) by 3 units.
Since the car stops at 2, the
answer to 5 – 3 must be 2.
Click to see the next example.
28. Example 4: (-4) – 2
1. Our car still starts at 0 facing
right.
2. It then backs up 4 units because it
sees the negative symbol - in front
of 4.
(Click to see animation.)
29. Example 4: (-4) – 2
1. Our car still starts at 0 facing
right.
2. It then backs up 4 units because it
sees the negative symbol - in front
of 4.
30. Example 4: (-4) – 2
1. Our car still starts at 0 facing
right.
2. It then backs up 4 units because it
sees the negative symbol - in front
of 4.
31. Example 4: (-4) – 2
1. Our car still starts at 0 facing
right.
2. It then backs up 4 units because it
sees the negative symbol - in front
of 4.
32. Example 4: (-4) – 2
1. Our car still starts at 0 facing
right.
2. It then backs up 4 units because it
sees the negative symbol - in front
of 4.
3. Now it has turn around because
of the subtraction symbol –.
(click to go on)
33. Example 4: (-4) – 2
1. Our car still starts at 0 facing
right.
2. It then backs up 4 units because it
sees the negative symbol - in front
of 4.
3. Now it has turn around because
of the subtraction symbol –.
34. Example 4: (-4) – 2
1. Our car still starts at 0 facing
right.
2. It then backs up 4 units because it
sees the negative symbol - in front
of 4.
3. Now it has turn around because
of the subtraction symbol –.
35. Example 4: (-4) – 2
4. Finally it moves forward by 2
units.
(click to go on)
40. Example 4: (-4) – 2
4. Finally it moves forward by 2
units.
The car now stops at -6, therefore
the answer to (-4) – 2 is -6.
Click to see the next example.
41. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
(Click to see animation)
42. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
43. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
44. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
45. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
46. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
3. Now the car has to turn around
because it sees the subtraction
sign.
(Click to see the next animation)
47. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
3. Now the car has to turn around
because it sees the subtraction
sign.
48. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
3. Now the car has to turn around
because it sees the subtraction
sign.
49. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
3. Now the car has to turn around
because it sees the subtraction
sign.
4. It then backs up 3 steps because it
sees the negative sign.
(click to see animation)
50. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
3. Now the car has to turn around
because it sees the subtraction
sign.
4. It then backs up 3 steps because it
sees the negative sign.
51. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
3. Now the car has to turn around
because it sees the subtraction
sign.
4. It then backs up 3 steps because it
sees the negative sign.
52. Example 5: 2 – (-3)
1. Our car starts from 0 facing
right.
2. It then moves 2 units to the right.
3. Now the car has to turn around
because it sees the subtraction
sign.
4. It then backs up 3 steps because it
sees the negative sign.
Since the car stops at 5, the
answer to 2 – (-3) is 5.
Click to see the next example.
53. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
(click to see animation)
54. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
55. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
56. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
57. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
58. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
3. Next it has to turn around because it sees
the – sign.
(click to see animation)
59. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
3. Next it has to turn around because it sees
the – sign.
60. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
3. Next it has to turn around because it sees
the – sign.
61. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
3. Next it has to turn around because it sees
the – sign.
4. Finally it has to back up 5 units because
the next number is -5.
(click to see animation)
62. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
3. Next it has to turn around because it sees
the – sign.
4. Finally it has to back up 5 units because
the next number is -5.
63. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
3. Next it has to turn around because it sees
the – sign.
4. Finally it has to back up 5 units because
the next number is -5.
64. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
3. Next it has to turn around because it sees
the – sign.
4. Finally it has to back up 5 units because
the next number is -5.
65. Example 6: (-3) – (-5)
1. Our car starts from 0 facing right.
2. It backs up 3 units in the beginning
because it sees a - sign in front of the 3.
3. Next it has to turn around because it sees
the – sign.
4. Finally it has to back up 5 units because
the next number is -5.
The answer is therefore +2.
The End, thanks for watching!
