Percentages are all around us...we just don't see it most of the time.
We may need to calculate increases... these are sometimes good like a pay rise,( i wish) but can also be bad, like bills rising each year. (to true)
We may also need to calculate percentage decreases ... sometimes good like a tax bill decreasing, or sometimes bad like the value of a car reducing.
Has he got bigger, or have I got smaller?
To find a percentage increase we use a multiplier.
If we want to increase 350 by 22% we use the multiplier 350 x 1.22 which equals 427
(this means we take the whole amount of 350 and add 22% to it).
So if we want to increase 241 by 18% the multiplier is 241 x 1.18 = 284.38.
Decreasing 350 by 22% we just do 350 x 0.22 right? Using 0 because we are decreasing. NO, NO, NO
Care is needed here. Remember percent means 'out of 100'.
To decrease we need a little more work.
We need to take the 22% from 100% first. So, 100 - 22 = 78 (we only want to find the 78% that is left).
To complete the decrease the multiplier is 350 x 0.78 = 273
So decrease 42 by 18% = 100 - 18 = 82% and therefore, 42 x 0.82 = 34.44
Take it slowly and you will get there..