Math

 The decimal to percent

One use for decimals is in working with percents, which are commonplace in everyday life:

the dress was on sale for 40% off the original price;
housing costs rose 5% last year;
there was a 150% increase in telephone activity after the newspaper advertisement.
There are 100 cents in a dollar.
A century is 100 years.
The word  percent  means  per one hundred .

The symbol  %  is used for percent.
Whenever you see the symbol   % , you can trade it in for a factor of 1100.
Whenever you see a factor of 1100, it can be traded in for a  %  symbol.
This simple idea is the key to success with percents:


Indeed, the symbol  %  even looks a bit like the fraction 1100;
it has the two zeros and the division bar!

To change from a decimal to a percent,
move the decimal point two places to the right and insert the percent symbol.

EXAMPLES:
0.03=3%

2.5=250%

1.008=100.8%
Here's the idea that makes this work:

0.03=3100=3⋅1100=3%

Notice that the 1100 gets traded in for the percent symbol.


Worksheet


1a.   0.26 =
1b.   0.95 =
1c.   0.61 =
1d.   0.17 =
1e.   0.11 =
2a.   0.04 =
2b.   0.49 =
2c.   0.92 =
2d.   0.19 =
2e.   0.46 =
3a.   0.45 =
3b.   0.7 =
3c.   0.69 =
3d.   0.08 =
3e.   0.3 =
4a.   0.07 =
4b.   0.27 =
4c.   0.48 =
4d.   0.35 =
4e.   0.43 =
5a.   0.85 =
5b.   0.65 =
5c.   0.83 =
5d.   0.36 =
5e.   0.96 =
6a.   0.79 =
6b.   0.63 =
6c.   0.91 =
6d.   0.53 =
6e.   0.35 =

Answer

1a.   26%
 
1b.   95%
 
1c.   61%
 
1d.   17%
 
1e.   11%
 
2a.   4%
 
2b.   49%
 
2c.   92%
 
2d.   19%
 
2e.   46%
 
3a.   45%
 
3b.   70%
 
3c.   69%
 
3d.   8%
 
3e.   30%
 
4a.   7%
 
4b.   27%
 
4c.   48%
 
4d.   35%
 
4e.   43%
 
5a.   85%
 
5b.   65%
 
5c.   83%
 
5d.   36%
 
5e.   96%
 
6a.   79%
 
6b.   63%
 
6c.   91%
 
6d.   53%
 
6e.   35%




























































































Comments