Percentages – Fractions Conversions:
The following is a table showing the conversions of percentages and decimals into fractions:
Percentage Decimal Fraction
10% 0.1 1/10
12.5% 0.125 1/8
16.66% 0.1666 1/6
20% 0.2 1/5
25% 0.25 1/4
30% 0.3 3/10
33.33% 0.3333 1/3
40% 0.4 2/5
50% 0.5 1/2
60% 0.6 3/5
62.5% 0.625 5/8
66.66% 0.6666 2/3
70% 0.7 7/10
75% 0.75 3/4
80% 0.8 4/5
83.33% 0.8333 5/6
90% 0.9 9/10
100% 1.0 1
Similarly we can go for converting decimals more than 1 from the knowledge of the above cited conversions as follows:
We know that 12.5% = 0.125 = 1/8
Then, 1.125 = [8(1)+1]/8 = 9/8 (i.e., the denominator will add to numerator once, denominator remaining the same.
Also, 2.125 = [8(2)+1]/8 = 17/8 (here the denominator is added to numerator twice)
3.125 = [8(3)+1]/8 = 25/8 and so on.
Thus we can derive the fractions for decimals more than 1 by using those les than 1.
We will see how use of fractions will reduce the time for calculations:
Eg: What is 62.5% of 320?
Soln: Value = (5/8) X 320 (since 62.5% = 5/8)
= 200.
