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.

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.

Example 1: 2 + 41. Our car starts from 0 facing

right.2. It then moves 2 units to the right

(click to see animation)

Example 1: 2 + 41. Our car starts from 0 facing

right.2. It then moves 2 units to the right

Example 1: 2 + 41. Our car starts from 0 facing

right.2. It then moves 2 units to the right

Example 1: 2 + 41. Our car starts from 0 facing

right.2. It then moves 2 units to the right.

Example 1: 2 + 41. 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.)

Example 1: 2 + 41. 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.)

Example 1: 2 + 41. 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)

Example 2: (-2 ) + 51. 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)

Example 2: (-2 ) + 51. Our car starts from 0 facing

right.2. It then backs up 2 units (to the

left) because it sees the - sign.

Example 2: (-2 ) + 51. Our car starts from 0 facing

right.2. It then backs up 2 units (to the

left) because it sees the - sign.

Example 2: (-2 ) + 51. 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)

Example 2: (-2 ) + 51. 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.

Example 2: (-2 ) + 51. 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.

Example 2: (-2 ) + 51. 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.

Subtraction1. 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.

Example 3: 5 – 31. Our car still starts at 0 facing

right.2. It then moves forward 5 units.

(Click to start animation)

Example 3: 5 – 31. Our car still starts at 0 facing

right.2. It then moves forward 5 units.

Example 3: 5 – 31. Our car still starts at 0 facing

right.2. It then moves forward 5 units.

Example 3: 5 – 31. Our car still starts at 0 facing

right.2. It then moves forward 5 units.

Example 3: 5 – 31. 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.

Example 3: 5 – 31. 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 – .

Example 3: 5 – 31. 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 – .

Example 3: 5 – 31. 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.

Example 3: 5 – 31. 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.

Example 3: 5 – 31. 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.

Example 4: (-4) – 21. 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.)

Example 4: (-4) – 21. 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.

Example 4: (-4) – 21. 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.

Example 4: (-4) – 21. 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.

Example 4: (-4) – 21. 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)

Example 4: (-4) – 21. 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 –.

Example 4: (-4) – 21. 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 –.

Example 4: (-4) – 2

4. Finally it moves forward by 2 units.

(click to go on)

Example 4: (-4) – 2

4. Finally it moves forward by 2 units.

Example 4: (-4) – 2

4. Finally it moves forward by 2 units.

Example 4: (-4) – 2

4. Finally it moves forward by 2 units.

Example 4: (-4) – 2

4. Finally it moves forward by 2 units.

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.

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)

Example 5: 2 – (-3)1. Our car starts from 0 facing

right.2. It then moves 2 units to the right.

Example 5: 2 – (-3)1. Our car starts from 0 facing

right.2. It then moves 2 units to the right.

Example 5: 2 – (-3)1. Our car starts from 0 facing

right.2. It then moves 2 units to the right.

Example 5: 2 – (-3)1. Our car starts from 0 facing

right.2. It then moves 2 units to the right.

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)

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.

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.

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)

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.

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.

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.

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)

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.

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.

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.

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.

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)

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.

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.

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)

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.

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.

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.

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!