| When we write "one dollar" we sometimes write: | ||
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$1.00 |
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| That is because our money is divided up | ||
| into pieces of dollars called cents. | ||
| The number on the right of the period | ||
| (in math we call it a decimal point) | ||
| are for those pieces of a dollar. | ||
| To write a quarter (also known as 25 cents), we can write: | ||
|
$0.25 |
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| Two quarters (sometimes known as 50 cents but never 50 cent) | ||
| looks like this: | ||
|
$0.50 |
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| The "S" with a line through it is just a code. | ||
| This code says we're talking about dollars or pieces of dollars. | ||
| It's not really part of the number. | ||
| We could use addition and add two quarters | ||
| to get 50 cents like this: | ||
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| If we start with two quarters (fifty cents) | ||
| and add another two quarters (fifty cents), | ||
| it looks like this: | ||
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| No big surprise here. | ||
| Most people know that 4 quarters is the same as a dollar. | ||
| The big thing is to see how these numbers add together. | ||
| WHEN YOU ADD THESE NUMBERS, | ||
| THE DECIMAL POINTS MUST LINE UP. | ||
| Example: | ||
| Add 38 cents plus 24 cents: | ||
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| We can do subtraction with this stuff too! | ||
| Example: | ||
| 81 cents minus 30 cents: | ||
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| The word cent comes from some foreign language. | ||
| It means 100. | ||
| There are 100 cents in a dollar. | ||
| This is like a pizza with 100 slices. | ||
| Each cent is one slice. | ||
| In our "slice of pizza" way of writing numbers, | ||
| we could write one cent like this: | ||
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| Using our new decimal point way, we can write one cent like this: | ||
|
$0.01 |
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| But hey! A penny is a penny no matter how you write it so: | ||
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| There are 4 quarters in one dollar. | ||
| Using the "pizza slice" fraction method, | ||
| we can say that there are 4 quarter sized slices in one dollar. | ||
| So for ONE quarter we can write: | ||
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| Using our new decimal point method | ||
| we can write one quarter (25 cents) as: | ||
|
$0.25 |
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| And a quarter is a quarter so: | ||
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Example: |
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| There are 10 dimes in a dollar (like a pizza with 10 slices) | ||
| each dime is also worth 10 cents. | ||
| If we wanted to add two dimes together we could write: | ||
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| And we could also write: | ||
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|
copyright 2005 Bruce Kirkpatrick |
