Per Cent - what to get out of a hundred.

The term Per cent is a natural extension of our base 10 number system. As a child we are introduced to the number system and the symbols that make up this language of math. We learn to count to 10, forwards and backwards and then extend all the way up to 100 as we begin understanding groups of ten as the building blocks for counting. This creates a good understanding or awareness of the number 100., which appears to be the reason that the term and use of ' per cent' is used so often when communicating the size and importance of a mathematical fact.

 

 

Per cent simply means 'per hundred'. The symbol 25% is read 'twenty-five per cent' and simply means 25 out of 100. It is useful to be able to understand that a per cent can be converted to a fraction and a decimal. 25% also mean 25/100 which can be reduced to 1/4 and 0.25 when written as a decimal

To change a fraction into a decimal or a per cent:

Begin with 5/8. Take your calculator (or pencil and paper) and divide 5 by 8 to get 0.625, now move the decimal over two places for the per cent. Thus 5/8 = 0.625 and 62.5/100. The important thing to understand is that if someone says 5/8 of the time light is red' , it is not as well understood as when someone says' 62 % of the time the light is red.'

Applying what you know:

You see an item that is $50.00, but it is being reduced by 15%. First you must decide what the amount is that is going to be deducted from $50.00 To do this you will need to multiply 50.00 by .15 (you need to convert 15% to a decimal). The answer is 7.5, now you will need to subtract $7.50 from $50.00, you will be paying $42.50 for the item that is on sale.

There are handy online tool to check your problems on percentages.