You first need to decide how close you need to get. By that, I mean, for example, do you need to know to the closest 1/16 or to the closest 1/64. Choose the denominator you want, such as 32, and multiply by the decimal. The answer will be the numerator of your fraction - though you will probably have to round it to the nearest whole number. (Remember that the numerator of a fraction is on top, the denominator is on the bottom.)
As an example, take the decimal 0.431 and convert. I will choose to convert to the nearest 64th. So:
0.431 x 64 = 27.584 --> rounded to 28 since it is more than 27.5
Your fraction is then 28/64. You would not use this fraction, though, since it is not in its most reduced form. Eventually you would probably learn your fractions well enough to know the equivalence by sight, but for the purposes of this explanation, lets do the math.
28/64 = 14/32 = 7/16
Since the numerator is odd, it is now reduced as far as possible.
As an example, take the decimal 0.431 and convert. I will choose to convert to the nearest 64th. So:
0.431 x 64 = 27.584 --> rounded to 28 since it is more than 27.5
Your fraction is then 28/64. You would not use this fraction, though, since it is not in its most reduced form. Eventually you would probably learn your fractions well enough to know the equivalence by sight, but for the purposes of this explanation, lets do the math.
28/64 = 14/32 = 7/16
Since the numerator is odd, it is now reduced as far as possible.