9.4 Adding Integers with Tiles Mme DiMarco

 Learning Goal: Use coloured tiles to add integers Learning Goal

 When you add two numbers, such as 5 + 3, you combine 5 counters with 3 counters to obtain 8 counters  You can add two integers in a similar way.  You know that +1 and -1 combine to make a zero pair.  We can combine coloured tiles to add integers. Recall + =

 (+5) + (+4)  Model each integer with tiles  +5:  +4: To add two positive integers Combine the tiles: In total there are 9 blue tiles THEREFORE, (+5) + (+4) = +9

 (-6) + (+9)  Model each integer with tiles  -6:  +9: To add a negative with a positive Combine the tiles: There are 6 zero pairs that cancel each other out. There are 3 blue tiles left. THEREFORE, (-6) + (+9) = +3

 (-3) + (-7)  Model each integer with tiles  -3:  -7: To add two negative integers Combine the tiles: There are 10 orange tiles in total. THEREFORE, (-3) + (-7) = -10

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