Then: divide the decrease by the original number and multiply the answer by 100.
The difference between the average and the actual rainfall can now be calculated: 320 - 260.2 = 59.8.
The formula for calculating percentages or for converting from percentages are relatively simple.
If we know the average rainfall is 250mm then we can work out the rainfall for the period using: the sum 250 + 23%.
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Examples and links to related resources are listed by sub-categories under the subject headings below
Then divide the decrease by the original number (February hours) so:
Take the example of “UK rainfall this summer was 23% above average” – we can tell immediately that the UK experienced almost a quarter (25%) more rainfall than average over the summer. However, without knowing either what the average rainfall is or how much rain fell over the period in question we cannot work out how much rain actually fell.
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Furey, Edward "Percentage Calculator" From http://www.CalculatorSoup.com - Online Calculator Resource.
Combining the calculations you can get the formula for Y/P% = Y/(P/100) = X so 15/10% = 15/(10/100) = 150
#3: Calculating with Percent e.g. 6 out of 8 is what % and 15 is 30% of what?
In the above example, I first had to figure out what the actual tax was. Many percentage problems are really "two-part-ers" like this: they involve some kind of increase or decrease relative to some original value. Warning: Always figure the percentage of change relative to the original value.
Stapel, Elizabeth. "Basic 'Percent of' Word Problems." Purplemath. Available from http://www.purplemath.com/modules/percntof.htm. Accessed [Date] [Month] 2016
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320 ÷ 1.23 = 260.1626. Rounded to one decimal place, the average rainfall is 260.2.
We can conclude that 59.8 is 23% of the average rainfall amount (260.2), and that in real terms 59.8mm more rain than average fell.
The guidance below will help you work through percentage calculation problems including those found on the percentage worksheets page.
Handy Tip: A good way of finding percentages is to start by finding what 1% is.
A large number and variety of printable math worksheets all with optional answer pages.
Here we have the rate (35%) and the original number (80); the unknown is the comparative number which constitutes 35% of 80. Since the exercise statement is "(some number) is (thirty-five percent) of (eighty)", then the variable stands for a number and the equation is:
Sometimes both the percentage and amount of money will not be whole numbers.
Use this calculator to work out the percentage change of two numbers
Percentage problems usually work off of some version of the sentence "(this) is (some percentage) of (that)", which translates to "(this) = (some decimal) × (that)". You will be given two of the values, or at least enough information that you can figure two of them out. Then you'll need to pick a variable for the value you don't have, write an equation, and solve for that variable.
Decimals can be written as a percentages by moving the decimal point two places to the right:
Easy-to-use games for practicing multiplication, math facts, equivalent fractions, and more.
How to find a percentage
First: work out the difference (decrease) between the two numbers you are comparing.
Then: divide the increase by the original number and multiply the answer by 100.
Original URL: http://www.purplemath.com/modules/percntof.htm -->
To convert a percentage to a fraction, divide by 100 and reduce the fraction (if possible):
Since x stands for a percentage, I need to remember to convert this decimal back into a percentage:
Practise converting percentages to fractions. Then try the questions below.
Here we have the rate (45%) and the comparative number (9); the unknown is the original number that 9 is 45% of. The statement is "(nine) is (forty-five percent) of (some number)", so the variable stands for a number, and the equation is:
A car costs £9,999.90 before VAT (value added tax). Work out the cost of the VAT if it is charged at 20%.
An understanding of percent allows students to estimate to check whether their answer is reasonable. In this example, knowing that 35% is between one-quarter and one-half would mean the answer should be somewhere between 20 and 40.
First work out 1% of 250, 250 ÷ 100 = 2.5 then multiply the answer by 23, because there was a 23% increase in rainfall.
First: work out the difference (increase) between the two numbers you are comparing.
Weisstein, Eric W. "Percent." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/Percent.html
Percentages can be written as decimals by moving the decimal point two places to the left:
Dylan therefore worked 30% more hours in February than he did in January.