Addition | Answer | Example |
Sum of two positive integers | is always a positive number | 4 + 5 = 9 |
Sum of a positive and negative integer | is either positive or a negative number | 3 + -4 = -1 8 + -2 = 8 - 2 = 6 |
Sum of a negative and positive | is either positive number or a negative number | -3 + 4 = 1 -6 + 2 = -4 |
Sum of a two negative integers | is always a negative number | -3 + -4 = -7 -6 + -2 = -6 - 2 = -8 |
Subtraction | Answer | Example |
Difference of two positive integers | is either positive or a negative number | 7 - 5 = 2 5 - 7 = -2 |
Difference of a positive and negative integer | is always positive number | 3 - -4 = 3 + 4 = 7 6 - -2 = 8 |
Difference of a negative and positive integer | is always negative number | -3 - +4 = -3 - 4 = -7 -8 - +2 = -8 - 2 = -10 |
Difference of a two negative integers | is either positive or a negative number | -3 - -4 = -3 + 4 = 1 -6 - -2 = -6 + 2 = -4 |
Method:
- When there are two numbers, one positive and the other negative, subtract and use the sign of the greater number.
- When two numbers are of the same sign, add and use the sign the numbers have,
- When there is a negative sign, before a negative number, it becomes a positive number.
- When there is a positive sign, before a negative number, it remains unchanged.
Example: -4-5
Since the signs are same, add and use the negative sign.
Answer: -9
Example: 4 -(-3)
When there is a negative sign before the negative number, it becomes a positive number
4+3
Answer: 7
Example: 7 +(-3)
When there is a positive sign before the negative number, it remains unchanged
7-3
Answer: 4
Negative numbers are used in many ways, including financial statements, altitude measurements, temperature, golf scores and atomic changes.
Directions: Solve the following. Also write 5 examples of each kind.
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