How to add and subtract integers

1. How to add and subtract Integers?

2. Modeling integer addition using colored counters Let yellow color represent positive integers and the red color represent the negative integers. Example : Let us find the value of 7 + (-3) Show 7 yellow (positive) counters and add 3 red (negative) counters + + + + + + + + + + + To add integers with different signs, use zero pairs. Remember + 1 – 1 = 0 Take out the zero pair (one yellow and one yellow makes a zero pair). The remainder is the answer. _ _ _

3. Integer Addition: Find (-5) + (-2) Show 5 red (negative) counters. Then add 2 red counters. Together there are 7 Red counters. So (-5) + (-2) = -7 _ _ _ _ _ _ _ _ _ _ _ _ _ _

4. Integer Addition Find (- 4) + 3. _ _ _ _ _ Show 4 Red counters and then add 3 Yellow counters. Pair the Red and Yellow counters. Remove the Zero pairs. There is one negative counter left. So (-4) + 3 = -1 + + +

5. Modeling integer subtraction using colored counters Example 1: Find 6 – 3 + + + + + + + + + + + + + + + Remember Subtraction means take away. Show 6 positive counters and take away three counters. There are 3 positive counters left. So there are 3 positive counters left. Therefore, 6 – 3 = 3

6. Integer Subtraction Example 2: Find - 6 – (-3) Show 6 red (negative) counters. Take away 3 red counters. We are left with 3 red counters. Therefore, -6 – (-3) = -3 - - - - - - - - - - - - - - -

7. Integer Subtraction Example 3: Find 6 – (-2) Show 6 positive yellow counters. Insert two zero pairs. Then take away 2 negative counters. There are 8 positive counters left. So 6 – (-2) = 8 + + + + + + + + + + + + + + - -