can someone help me ?

thenightrider

Hi im doing some study for a maths exam next week im stuck on one section and dont know how to work it out could some one help ?

Its Converting different number base's in to other's i can do one side of the decimal point but not the fraction side of it.

Eg
2ED.4C to base 10 i can get the 2ED part but dont know hoe to work out the .4C

thenightrider

I think i worked it out but not 100 % sure 749.296875

MathsManiac

I got the same answer as you. The first digit after the "decimal" point is sixteenths, the next is 256ths, and so on.

2ED.4C is therefore: 2*4096 + 14*256 + 13*16 + 4*(1/16) + 12 * (1/256)

bnt

Aoother way to do this is:
- make note of the number of fraction digits (f) behind the decimal point (f = 2)
- convert without the decimal point (2ED4Ch => 191820)
- divide the result by base^f: 191820 / (16^2) = 191820/256 = 749.296875

Delphi91

Another approach:

Count the number of characters BEFORE the decimal point (n=3).

Multiply the first character by 16^(n-1), the second by 16^(n-2) etc until you get to the end. Evaluate each term and add them up i.e.

[latex]\displaystyle {2 \times 16^2} + {E \times 16^1} + {D \times 16^0} + {4 \times 16^{-1}} + {C \times 16^{-2}}\\ [/latex]

Converting the letters to their respective numbers gives:

[latex]\displaystyle = 2 \times 256 + 14 \times 16 + 13 \times 1 + 4 \times 0.0625 + 12 \times 0.0039\\ [/latex]

[latex]\displaystyle $$= 512 $ + $ 240 $ + $ 13 $ + $ 0.25 $ + $ 0.0468$$\\ [/latex]

[latex]\displaystyle = 765.2968_{10}[/latex]