What you need to know

Things to remember:

  • To convert a percentage into a decimal we divide by 100.
  • To divide by 100 we move all the digits right 2 places.

First, let’s break up the word “percent” into “per” and “cent”.

per – “for every” or “out of”

cent – 100 (Century = 100 years)

So, if we put these together, then “percent” means “for every 100” or “out of 100”. Writing “percent” takes waaaaaaaay too long, so we use the symbol %.

10% – 10 percent

25% – 25 percent

47% – 47 percent

So, something like 47% just means “47 out of every 100”. We could show this percentage by cutting a block into 100 pieces and taking 47 of them:

 

 

So really, a percentage is actually just dividing by 100!

 

47\% =47\div100=0.47

 

Remember: To divide by 100 we move all of the digits right one place.

 

So, to covert a percentage into a decimal we just divide by 100!

 

5\% =5\div100=0.05

23\% =23\div100=0.23

146\% =146\div100=1.46

Example Questions

Question 1: Convert 65% into a decimal.

Answer

65%=65\div100=0.65

Question 2: Convert 250% into a decimal.

Answer

250%=250\div100=2.50=2.5