Number system provides various types of number patterns to solve various types of problems. From those number patterns, we are going to discuss about the positive and negative numbers. In general aspect, both can be considered as integer. |

Given below are the rules to be followed when adding positive and negative numbers:

- If the signs of both the numbers are same, ignore the signs and add the numbers. In the result, put the sign of addends in front of the answer.
- When the signs are different, pretend the signs aren't there. Subtract the smaller from the larger one and put the sign of the larger one in front of your answer.

### Solved Example

**Question:**Add -4 + 8

**Solution:**

**Given:**-4 + 8

We know that -4 + 8 = 4

As 8 is larger and the sign is positive, we get 8 as the solution. (No need to change the sign)

Therefore, -4 + 8 = 8 - 4 = 4

- Two like signs become a positive sign and two unlike signs become a negative sign.
- When the signs are different, subtract the smaller value from the larger value. Place the sign of the larger value in the solution.

### Solved Example

**Question:**Solve 21 - (+ 2).

**Solution:**

**Given:**21 - (+2)

We know that 21 - 2 = 19

As 21 is larger and the sign is positive, we get 19 as the solution.

Therefore, 21 - (+2) = 19

- If both factors are positive, the product will be positive.
- If both factors are negative, the product will be positive.
- If any one of the factors is negative, the product will be negative.

### Solved Examples

**Question 1:**What is the product of -9 and 27?

**Solution:**

**To find:** -9 x 27

As one of the factors is negative, the product is negative.

Therefore, the solution of -9 x 27 is -243.

**Question 2:**What is the product of (-4), (5) and (-2)?

**Solution:**

(-4) x (5) = -20

Now, multiply (-20) and (-2)

We get (-20) x (-2) = 40 (Two like signs gives a positive sign)

Therefore, Product of (-4), (5) and (-2) is 40.

- If both the dividend and divisor are positive, the quotient will be positive.
- If both the dividend and divisor are negative, the quotient will be positive.
- If any one of the dividend or divisor is negative, the quotient will be negative.

### Solved Examples

**Question 1:**Solve $\frac{28}{7}$

**Solution:**

Therefore, $\frac{28}{7}$ = 4

**Question 2:**Solve $\frac{135}{-15}$

**Solution:**

**To find:** $\frac{135}{-15}$

$\frac{135}{15}$ = 9 (Two unlike signs become a negative sign)

Therefore, $\frac{135}{-15}$ = -9