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Computing AQA CPT4- MODULE 4 watch

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    how did you find it?

    did u get -1.25 for the decimal number on that floating point question?
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    bump
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    There was a floating point question?
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    floating point wtf? i just remember it saying take 6 from 18 or something and SHOW how the steps are done
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    It said what was the hex number A802 in binary, and decimal, when stored using floating point (12 bit mantissa, 4 bit exponant)


    -1.25 anyone?
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    (Original post by friday13th)
    It said what was the hex number A802 in binary, and decimal, when stored using floating point (12 bit mantissa, 4 bit exponant)


    -1.25 anyone?
    ah right, i just converted the hex number into binary then binary into decimal, cant remember what i got tho
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    (Original post by friday13th)
    It said what was the hex number A802 in binary, and decimal, when stored using floating point (12 bit mantissa, 4 bit exponant)


    -1.25 anyone?
    Did it say in floating point???
    Oops!
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    Hang on, i don't think it was floating point.
    There was no room to work out the answer, and it wasn't worth enough points for a floating point Q, i thought.
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    It said it had a 12 bit mantissa, and a 4 bit exponant!!!

    So it has to be floating point

    listen

    A802 = hex
    1010100000000010 = binary


    [1] [01010000000] [0010]


    [1] = sign bit= negative so the number is - something
    [0010] = exponant = 2 in decimal, which means u move the decimal point 2 places

    so take the mantissa and move the decimal point two places

    1.010000.... is what you get

    in decimal this is

    1.25

    and the answer is -1.25


    please tell me i am right


    yes the question was only four marks

    yeah it was floating point, was 4 marks (one for convering to binary, three for converting that binary number into decimal using twos complement) i got -2.75, i think the number was 1010100000000010

    (Original post by friday13th)
    It said it had a 12 bit mantissa, and a 4 bit exponant!!!

    So it has to be floating point

    listen

    A802 = hex
    1010100000000010 = binary


    [1] [01010000000] [0010]


    [1] = sign bit= negative so the number is - something
    [0010] = exponant = 2 in decimal, which means u move the decimal point 2 places

    so take the mantissa and move the decimal point two places

    1.010000.... is what you get

    in decimal this is

    1.25

    and the answer is -1.25


    please tell me i am right


    yes the question was only four marks
    i thought it was 101.01 after moving two places to the right
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    Oh, you dont include the sine bit in the moving the decimal point...s-man
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    how about showing 6 take away from 18?

    first i said its the same as 18 + ( - 6 )
    u can either make the most significant bit NEGATIVE or get the binary for the number 6, then INVERT THE BITS and then add one

    then i added 18 to 6 ( minus 6 ) which gave correct answer ( in binary ) and u can check the answer in binary with 18 - 6
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    (Original post by Iluvatar)
    I thought you had to do both?
    as long as u include the method and calculate the correct answer its all good
    i just mentioned u had to invert, add 1, make the msp a minus and then calculate, carrying the 1's when there were a double one etc
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    You are right friday13th it was -1.25, dunno what every1 else is on about
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    thank you god


    thats the only page i got marks on lol
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    ya, I cocked the conversion of the -1.25 bit up.

    The 18-6 was pretty straightforward... convert +6 into -6, then add it.

    So 18 + (-6).

    Came out with 12 in binary... I think that was right :P
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    (Original post by KiLLeRSpaM)
    ya, I cocked the conversion of the -1.25 bit up.

    The 18-6 was pretty straightforward... convert +6 into -6, then add it.

    So 18 + (-6).

    Came out with 12 in binary... I think that was right :P
    ye thats right any1 get wat the algorithm does?

    for the floating point q:


    mantissa=101010000000= [-(2^11)+(2^9)+(2^7)] / (2^11) = (-11/16)

    exponent= 0010= 2^2 = 4

    answer = (-11/16) * 4 = -2.75

    the method also matches all the floating point questions given in past papers

    (Original post by jay9386)
    ye thats right any1 get wat the algorithm does?
    binary search is what i put
 
 
 
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