Answer:

Step-by-step explanation:
Given

Required
Determine the remainder
Write down the first digit i.e. 1. So, we have:

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Multiply that 1 by the divisor (1) i.e. 
Write down the result under the next digit i.e. (under 2)


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Sum 2 and 1 i.e 


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Multiply that 3 by the divisor (1) i.e. 
Write down the result under the next digit i.e. (under -3)


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Sum -3 and 3 i.e 


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Multiply that 0 by the divisor (1) i.e. 
Write down the result under the next digit i.e. (under 3)


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Sum 3 and 0 i.e 
Since there is no other computation to do, the result of the last sum is the remainder.
So:
