Business Mathematics

1. Conversions of decimal ,
fraction and percentage
Prepared by: Mr. George G. Lescano

2. Conversion of fraction to decimal
• In fractions, the numerator is the number above the line and
the denominator is the number below.
• The line in a fraction that separates the numerator and
the denominator represents division.
• To convert a fraction to a decimal, divide the numerator by
the denominator.

3. Conversion of fraction to decimal
Examples:
⁴/₅ as a decimal is 4 ÷ 5 = 0.8
⁷⁵/₁₀₀ as a decimal is 75 ÷100 = 0.75
³/₆ as a decimal is 3 ÷ 6 = 0.5

4. Conversion of fraction to percent
Simplest Method:
Divide the top of the fraction by the bottom
Then multiply the result by 100 and read off the answer !

5. Conversion of fraction to percent
Simplest Method:
Examples:
What is
5
8
as a percent?
5
8
= 0.625 0.625 multiply by 100 = 62.5%

6. Conversion of fraction to percent
Simplest Method:
After dividing, instead of
multiplying by 100 we can
just move the decimal
point 2 places to the right,
then add the %

7. Conversion of fraction to percent
Hardest Method:
Find a number you can multiply the bottom of the
fraction by to get 100.
Multiply both top and bottom of the fraction by that
number.

8. Conversion of fraction to percent
Hardest Method:
Then write down just the top number with the "%"
sign.

11. Conversion of fraction to decimal
• A fraction is made up of two parts: a numerator and
a denominator. It is used to represent how many parts we
have out of the total number of parts.
• The line in a fraction that separates the numerator and
denominator can be rewritten using the division symbol.

12. Conversion of fraction to decimal
• So, to convert a fraction to a decimal, divide the numerator by
the denominator. If required, you can use a calculator to do
this. This will give us our answer as a decimal.

13. Conversion of fraction to decimal
Examples:
⁴/₅ as a decimal is 4 ÷ 5 = 0.8
⁷⁵/₁₀₀ as a decimal is 75 ÷100 = 0.75
³/₆ as a decimal is 3 ÷ 6 = 0.5

14. Conversion of percent to fraction
Step 1: Write down the percent divided by 100 like this:
𝑝𝑒𝑟𝑐𝑒𝑛𝑡
100
Step 2: If the percent is not a whole number, then multiply both top
and bottom by 10 for every number after the decimal point. (For
example, if there is one number after the decimal, then use 10, if there
are two then use 100, etc.)
Step 3: Simplify (or reduce) the fraction

17. Conversion of decimal to percent
Converting from a decimal to a percentage is done by
multiplying the decimal value by 100 and adding %.
Example 1: 0.10 becomes 0.10 x 100 = 10%
Example 2: 0.675 becomes 0.675 x 100 = 67.5%

18. Conversion of decimal to percent
The shortcut to convert from decimal to percent is to move the
decimal point 2 places to the right and add a percent sign.

19. Conversion of percent to decimal
Converting from a percent to a decimal is done by removing the
percent sign % and dividing the value by 100.
Example 1: 15.6% becomes 15.6 / 100 = 0.156
Example 2: 235% becomes 235 / 100 = 2.35

20. Conversion of percent to decimal
The shortcut to convert from a percent to a decimal is to move the
decimal point 2 places to the left and remove the percent sign.

21. Quotation of the day!