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257 bytes added ,  09:16, 8 April 2010
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Subtraction is the inverse of addition. Move out beads that correspond to the number you are subtracting. You can "borrow" from the column immediately to the left: subtracting one unit and adding 10 to the current column.
 
Subtraction is the inverse of addition. Move out beads that correspond to the number you are subtracting. You can "borrow" from the column immediately to the left: subtracting one unit and adding 10 to the current column.
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'''Example:''' 26–2–4–6–10=4
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<gallery>
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File:Abacus-26.png|26
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File:Abacus-minus-2.png|–2=24
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File:Abacus-minus-4.png|–4=20
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File:Abacus-carry-10.png|carry 10 to the right
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File:Abacus-minus-6.png|–6=14
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File:Abacus-minus-10.png|–10=4
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</gallery>
    
'''TODO:''' Add instructions for multiplication and division.
 
'''TODO:''' Add instructions for multiplication and division.
    
[[Category:Activities]]
 
[[Category:Activities]]

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