D.S Method not woking

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  • #5102
    Harsh – Lecture
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    9128  –  5595 = 3533

    D.S Method Not working for this

    9128 = 2

    5595 = 6

    2-6 = -4  ??

    #5104
    Ofpad
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    Hi Harsh,

    Thank you for asking this question and I am not sure how I missed adding this in the lecture. When the subtraction of the DS is negative you add 9 to the negative number.

    21 – 14 = 7

    3 – 5 = -2 (+9) = 7.

    Another example

    24 – 7 = 17

    6 – 7 = -1 (+9) = 8 (Which is the digit sum of 17 = 1 + 7 = 8)

    For your particular problem

    9128 – 5595 = 3533

    2 – 6 = -4 (+9) = 5 (Which is the digit sum of 3533 = 5)

    Thank you for asking this question. Will update the lecture so its more clear. 🙂

    Hope this clarifies.

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