If you are having difficulty figuring out the percentage of an item and don't have a calculator, you may utilize this trick (which i still don't know how it came to be in my mind).(adsbygoogle = window.adsbygoogle || []).push({});

Let: ##a## be a fractional number (percentage) and ##b## a whole number.

If you make ##a## be a whole number as well,then:

##a\times b####=####ab##

Then proceed to divide the product ##ab## by 100: ##ab/100####=####n##

where n is the percentage of said item.

Example: What is 16% of 24.31$ ?

##16 \times 24##=##384##

##384/100####=####3.84##

Now: ##16\times31##=##496##

##496/100####=####4.96##

##4.96/100####=####0.0496##

##3.84+0.0496####=####3.8896##

Which can be approximated to: ##\approx 3.89##

Hope i can help people with this :)

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Fun base 10 application (Grocery Woes)

**Physics Forums | Science Articles, Homework Help, Discussion**