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Math Help - Unit digit

  1. #1
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    Question Unit digit

    What is the unit digit of the expansion (44)^4,(55)^5,(88)^8..
    I want the deep explanation... Please..
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  2. #2
    Junior Member Mrdavid445's Avatar
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    Re: Unit digit

    Well one way to do this problem is using mods... but I prefer this way:
    List out the units digits of powers of 4:
    4, 6, 4, 6, 4... see the pattern?
    For powers of 5, the units digit is always 5
    For powers of 8, we have the pattern 8, 4, 2, 6, 8, 4, 2, 6, 8...

    You can use this to help find your answer
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  3. #3
    MHF Contributor

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    Re: Unit digit

    Another way to do this is to simple do the arithmetic! 44^2= 1936, 44^3= 85184, and 44^4= 3748096.
    55^5= 503284375, 88^8=3596345248055296. Nothing "deep" about that!
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