Percentages are simply another way of expressing hundredths.

"Per cent" means "out of a hundred"

So 1% = **1/100**

10% = 10/100 = **1/10** when we reduce the fraction to its lowest terms

20% = 20/100 = 2/10 = **1/5**

43% = **43/100**

Remember that 50% and 5% are very different:

50% = 50/100 = **1/2**

5% = 5/100 =** 1/20**