Basically what this is, is:
100% = 100/100
Basically, to get the fraction, you just set the denominator as 100 and move the percentage up. You can then multiply by as many powers of 10 as needed or simplify the fraction as many times as needed.
Ex:
78.7% = ?/100
Just put 78.7 into that question mark spot to get:
78.7/100 = 78.7%
Now, you multiply the whole thing by 10/10:
787/1000
So that's your fraction.
29% = ?/100
Then it would be,
29/100.
55.8%: 558/1000, you could simplify that by dividing both the numerator and denominator by 2, and you would get 279/500.
28.2%: 282/1000, simplify that: 141/500
82%: 82/100, 41/50
74%: 74/100, 37/50
91.8%: 918/1000, 459/500
72%: 72/100, 18/25
129%: 129/100
15.8%: 158/1000, 79/500
24.3%: 243/1000
93%: 93/100
