Activities/Abacus: Difference between revisions
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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. | ||
'''Example:''' 26–2–4–6–10=4 | |||
<gallery> | |||
File:Abacus-26.png|26 | |||
File:Abacus-minus-2.png|–2=24 | |||
File:Abacus-minus-4.png|–4=20 | |||
File:Abacus-carry-10.png|carry 10 to the right | |||
File:Abacus-minus-6.png|–6=14 | |||
File:Abacus-minus-10.png|–10=4 | |||
</gallery> | |||
'''TODO:''' Add instructions for multiplication and division. | '''TODO:''' Add instructions for multiplication and division. | ||
[[Category:Activities]] | [[Category:Activities]] | ||