Adding Integers

1. Adding Integers

2. Adding Integers with the Same Sign • When adding integers with the same sign, the sum will be: • Positive if both integers are positive. • Negative if both integers are negative. Examples: 7 + 4 = 11 -7+ (-4) = -11

3. Additive Inverse Property • The integers 5 and -5 are called opposites because they are the same distance from zero, but on opposite sides of zero. • Two integers that are opposites are also called additive inverses. • The sum of any number and its additive inverse is 0 (zer0). • Example: 5+ (-5) = 0

4. Adding Integers with Different Signs • To add integers with different signs, subtract their absolute values. • The sum is: • Positive if the positive integer’s absolute value is greater. • Negative if the negative integer’s absolute value is greater. Examples: 9 + (-4) = 5 -9 + 4 = -5

5. Subtracting Integers • To subtract an integer, add its opposite. • Examples: • 4 – 9 = 4 + (-9) = -5 • 7 – (-10) = 7 + (10) = 17

6. Integer Cube Game • Each pair or group of 3 will be given 2 integer cubes. • In your group, take turns rolling the integer cubes. • The student who rolls writes an addition problem using the two integers from the roll and then finds the sum. • Each student must record his/her addition problems and the sums on a sheet of paper. • Each student is responsible for keeping a running total of his/her sums. • The first student in the group who reaches a sum of -15 wins!