There are a few ways of learning how to calculate percentages of whole numbers ..
.. although this video shows how to calculate percentages by converting to fractions and then cross division.
‘Percentage’ means ‘out of 100.’ Therefore we can use the idea of ‘equivalent fractions’ to make the numbers smaller and easier to deal with.
So 12% is exactly the same as 12/100; which is equivalent to 6/50 or 3/25.
Any number can be written as divided by 1.
So 50 is the same as 50/1 – we then use cross division to make a calculation.
The key points to remember are:
- ‘whatever we do to the top, we have to do to the bottom.’
- don’t forget that ‘of” always means ‘multiply.’
Finally, not all questions require you to answer as a decimal – it’s perfectly OK to leave as a fraction (providing you make sure it’s as small as possible).
This is a popular method that is taught in schools:
Why are percentages important?
Most of everyday life involves percentages, usually as a comparison.
For instance 30% discount seems a much better deal than 10%… or does it? (you really need to work out the actual price you pay).
Generally we tend to mix and match between fractions and percentages. Although it’s the same thing, 30% seems a lot friendlier than a discount of 3/10ths !
Watch the videos on YouTube:
https://www.youtube.com/watch?v=L_0T-WPQH18
https://www.youtube.com/watch?v=zM1DmuKLwkw
https://www.youtube.com/watch?v=j7VMJSTw1tE
[easyazon_image align=”none” height=”160″ identifier=”1447980204″ locale=”UK” src=”https://www.3minutemaths.co.uk/wp-content/uploads/2016/04/51PqY1BYYTL.SL160.jpg” tag=”matwra-21″ width=”118″]
Sean Dempsey says
your a lifesaver
ThealmightyFlinson says
if you don’t simplify would it be correct?
gaia Hill says
Thank you:)
sukr bait says
Why not just leave it as 50/200x 100= 25? Why add another whole step?
Andrew Adamian says
THANK YOU SOOO MUCH! Really appreciate it!
red reuben says
good
LetsLearnArabic says
You’re an awesome teacher, yeah I totally forgot how to do this also I
guess as a suggestion you could have simplified the end i.e. 36/5 by doing
36/10 then multiplying it by 2? I guess if your math is decent then long
division should be fine but I find it easier to do it that way?
I guess the suggestion is for your students, seeing your math is really
good.
andrejustin bayarong says
Thank you sir Simon Deacon for helping me answering my Ass.
Jiyat Singh says
thank you
Donal Gray says
Just letting you know that your final equation (37% of 600) was off by a
count of 60. You said 3 times 10% but only added it up to 120 rather than
180. Perfect bar that wee slip of the tongue.
Stephanie Anne says
You can do canceling. Example you divide 20 to 10. You can see there’s one
0 to 10 so your just gonna cancel how many zeros are there? Is it right?
Nicola Bean says
Brilliant, absolutely brilliant just what I needed thankyou so much 🙂
Great help
Tech Bliss says
best method, best way no doubt :D.
Number and Algebra – completed
Geometry and Measure – Completed
Statistics and Number – Tuesday 17th June 2014
The statistics and numbers is the one i fear very badly ): I will not do
good and it will reduce my grade by 50% lol
Usman Ikhlaq says
Excellent. Good for last minute revision!
Sage art says
U cud of just cancel out by 20 in the first place and 60 would have become
3 and the 100 would become 5 .
Johnny Bramble says
Thank you soooo much I am only in year 4 but I got level 5 questions during
the holidays and percentages was one of them
Johnny Bramble says
Thank you soooo much I am only in year 4 but I got level 5 questions during
the holidays and percentages was one of them
weelouisexo says
Can you tell me as I cannot find it anywhere.. How do you work out the
percentage difference between a number? Preferably on a calculator. For
example, calculate the difference between 5.0 and 5.4 as a percentage.
deerashini deerashni says
Thank u sooo mch…I forget it cause my exam was going tonbe the follow day
soo I got stree and forget abt it
Ziheng Liao says
Better than my teacher
Dudeloo Kanavos says
this is a bullsh*t method
Rasmus Haycraft Mee says
Thanks ALOT. By the looks of things I am going to be checking out quite a
few of your vids
sakina221 says
Thanks ur videos are really helping me in order to revise for my gcse mock
exam as I’m doing foundation for me to do higher have to pass foundation
I’m really grateful you explanations are much easier to understand
Simon Deacon says
Please post, pin, tweet, like or subscribe!
Simon Deacon says
Please post, pin, tweet, like or subscribe!
Ajandeen Ali says
thank you Mr you really helped me with this and thought me a very simple way in working out percentages ….. thanks alot
Awake Drake says
not bad at all-
Simon Deacon says
Thanks – really appreciate comment 🙂
Randy Munguia says
Great Vid!
Simon Deacon says
Thank you 🙂
Randy Munguia says
Excellent video!
Lord Razor says
your amazing