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Integer Addition & Subtraction. Using pegs and holes…. Setting it all up. We are going to look at adding ad subtracting integers using pegs and holes. A peg represents +1 A hole represents -1 So 5 pegs would be +5 and 3 holes would be -3
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Integer Addition & Subtraction Using pegs and holes…
Setting it all up We are going to look at adding ad subtracting integers using pegs and holes. A peg represents +1 A hole represents -1 So 5 pegs would be +5 and 3 holes would be -3 If a peg is put in a hole then you are left with neither a peg nor a hole, which is equivalent to zero. + = 0
Adding pegs and holes… Adding pegs and holes to the starting situation is straight forward. EG + = = 1 + =
Subtracting pegs and holes… This requires a little more thought… to take away a hole you need to add a peg (to fill it up) and to take away a peg you need to add a hole (for it to fall into). EG - = + =
Subtracting pegs and holes… EG - = + = =3