As your question combines three different kinds of numbers, it can be difficult to determine which part you having an issue with, however, this guide will hopefully explain all three possibilities well enough for you to decide which part you require.
Firstly, you have 66, if this is a whole number (an 'integer') then you do not need to convert it to anything, as it complete as it is. Any additional fraction, or part of another number you need to include with this can be put on the end, so 'sixty-six and three-quarters' (63 _) or 'sixty-three-point-four-two' (63.42) for example.
If your 66 is meant to be converted to a decimal, then you this will simply be 0.66, pronounced 'point-six-six' not 'point-sixty-six'.
So, onto your percentage, 'Per Cent' literally means 'per hundred', which is why 66 simply becomes 0.66. If you have any percentage, to convert it to a decimal, simply divide it by 100. 54% = 0.54, 99% = 0.99, 24% = 0.24 and 2.4% = 0.024.
As you have 2/3%, the assumption is that this means a part of 1%. If this is the case, you can simply divide the top part of the fraction (the numerator) by the bottom part (the denominator). Therefore, 2/3 = 0.666 recurring (meaning the 6s continue on to infinity).
However, as you have 66 2/3%, it is most likely that you intended this as one whole number. Hopefully, with the steps outlined above, you should be able to figure this out for yourself now. To figure it out, first convert your fraction into a decimal, so you have a single percentage. As 2/3 = 0.666 recurring, 66 2/3 = 66.666 recurring. Now you have a single percentage, as above, to convert a percentage to a decimal, divide by 100. So, 66.666/100 = 0.666 recurring. Therefore 66 2/3% equals 0.666, this is also equal to 2/3.
Firstly, you have 66, if this is a whole number (an 'integer') then you do not need to convert it to anything, as it complete as it is. Any additional fraction, or part of another number you need to include with this can be put on the end, so 'sixty-six and three-quarters' (63 _) or 'sixty-three-point-four-two' (63.42) for example.
If your 66 is meant to be converted to a decimal, then you this will simply be 0.66, pronounced 'point-six-six' not 'point-sixty-six'.
So, onto your percentage, 'Per Cent' literally means 'per hundred', which is why 66 simply becomes 0.66. If you have any percentage, to convert it to a decimal, simply divide it by 100. 54% = 0.54, 99% = 0.99, 24% = 0.24 and 2.4% = 0.024.
As you have 2/3%, the assumption is that this means a part of 1%. If this is the case, you can simply divide the top part of the fraction (the numerator) by the bottom part (the denominator). Therefore, 2/3 = 0.666 recurring (meaning the 6s continue on to infinity).
However, as you have 66 2/3%, it is most likely that you intended this as one whole number. Hopefully, with the steps outlined above, you should be able to figure this out for yourself now. To figure it out, first convert your fraction into a decimal, so you have a single percentage. As 2/3 = 0.666 recurring, 66 2/3 = 66.666 recurring. Now you have a single percentage, as above, to convert a percentage to a decimal, divide by 100. So, 66.666/100 = 0.666 recurring. Therefore 66 2/3% equals 0.666, this is also equal to 2/3.
