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Changing
a whole number into a percent
a) Write 7 as a percent. Find the invisible decimal. It's behind
the whole number. Move it 2 places to its right and place zeroes
in the two places. Therefore 7 = 700%
b) Write 14 as a percent. Find the invisible decimal. It's behind
the whole number. Move it 3 places to its right and place zeroes
in the two places. Therefore 14 = 1400 %
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Changing
a decimal to percent and back to decimal:
a) Write .34 as a percent = 34% - as percent
contains two zeros, move the decimal 2 places to the right, add
the percent sign. Note the decimal point is
invisible
b) Write 0.0085 as a percent = 0.85% as percent contains two zeros,
move the decimal 2 places to the right, add the percent sign after
the numbers.
c) Write 3.64 as a percent = 364% - as percent contains two zeros,
move the decimal two places to where the percent sign sits and add
the sign. Note the decimal point is invisible.
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Changing
a percent to a decimal:
a) Write 45% as a decimal = .45 - as percent
contains two zeros, move the decimal 2 places away from the percent
or to the left - drop the percent sign and add zeros as needed.
a) Write 70.4% as a decimal = .704 - as percent contains two zeros,
move the decimal 2 places away from the percent - or to the left
- drop the percent sign and add zeros as needed.
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Change a fraction to a decimal or percent and back:
a) Write 4/5 as a percent - first change 4/5
into a decimal- read the problem as 4 divided by 5. Write it as
a division problem - there is an invisible decimal after the 4 -
5 cannot to go into 4 -
Put in the invisible decimal and add a zero – it looks like
the answer is .8
(if you look at rule number 2) is 80%
b) Write 75% as a fraction -first convert a decimal 0.75-that read
words - seventy-five hundredths-now why to as a fraction 75 over
100 and be sure to reduce this to 3/4. HINT - count the number of
places after the decimal - replace with an equal number of zeros
- now place a one in front of the zero. Therefore 0.0702 = 702 over
10000 reduced = 301 over 5000.
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