Let's have fun with Decimals!!

8/14/2019 Let's have fun with Decimals!!

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DECIMALSDECIMALSBy Miss Sarah OthmanBy Miss Sarah Othman


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What is Decimals?What is Decimals?

A Decimal Number (based on the number10) contains a Decimal Point.


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Place ValuesPlace Values

To understand decimal numbers you mustfirst know about Place Value.

When we write numbers, the position (or

"place") of each number is important.
http://www.mathsisfun.com/place-value.htmlhttp://www.mathsisfun.com/place-value.html


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For ExampleFor Example

In the number 327:

the "7" is in the Units position, meaningjust 7 (or 7 "1"s),

the "2" is in the Tensposition meaning 2tens (or twenty),

and the "3" is in the Hundreds position,meaning 3 hundreds.


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Example continuesExample continues

"Three Hundred TwentySeven"


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As we move right,As we move right,each position is 10each position is 10timestimes smallersmaller!!FromFrom Hundreds, toHundreds, to

Tens, toTens, to UnitsUnits


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But what if we continue past Units?But what if we continue past Units?

What is 10 times smaller than Units?

1/10 ths (Tenths) are!

But we must first write a decimalpoint,so we know exactly where the Units

position is:

"three hundred twenty seven and four tenths"

And that is a Decimal Number!


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Decimal PointDecimal Point

The decimal point is the most important part of aDecimal Number. It is exactly to the right of theUnits position. Without it, we would be lost ...and not know what each position meant.

Now we can continue with smaller and smallervalues, from tenths, to hundredths, and so on,like in this example:


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Large and SmallLarge and Small

So, our Decimal System lets us write numbers as largeor as small as we want, using the decimal point.Numbers can be placed to the left or right of adecimal point, to indicate values greater than one orless than one.

17.591 The number to the left of the decimal point is a

whole number (17 for example) As we movefurther left, every number place gets 10 timesbigger. The first digit on the right means tenths(1/10). As we move further right, every numberplace gets 10 times smaller (one tenth as big).

hi k b i lW t thi k b t D i l
http://www.mathsisfun.com/whole-numbers.htmlhttp://www.mathsisfun.com/whole-numbers.html


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Ways to think about DecimalWays to think about DecimalNumbers .Numbers .

... as a Whole Number Plus Tenths, Hundredths,etc

You could think of a decimal number as a whole numberplus tenths, hundredths, etc:

Example 1: What is 2.3 ?

On the left side is "2", that is the whole number part. The 3 is in the "tenths" position, meaning "3 tenths", or

3/10

So, 2.3 is "2 and 3 tenths"

Example 2: What is 13.76 ?

On the left side is "13", that is the whole number part.

There are two digits on the right side, the 7 is in the"tenths" position, and the 6 is the "hundredths"position

So, 13.76 is "13 and 7 tenths and 6 hundredths"


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... as a Decimal Fraction... as a Decimal Fraction

Or, you could think of a decimalnumber as a Decimal Fraction.

re the denominator (the bott om num ber) is a number such as 10, 100, 1000, et

So "2.3" would look like this:

And "13.76" would look like this:

10

23

100

1367


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...... as a Whole Number and Decimalas a Whole Number and DecimalFractionFraction

Or, you could think of a decimal number asa Whole Number plus a Decimal Fraction.

So "2.3" would look like this:

And "13.76" would look like this:

10

32 and

13 and

100

67

Example: Add 1 452 to 1 3


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Adding DecimalsAdding Decimals

Adding decimals is easy if you keep yourworkneat

To add decimals, follow these steps:

, , Write down the numbers one under the other

.with the decimal points lined up

Add zeros so the numbers have the samelength

,Then add normally remembering to put thedecimal point in the answer

Example: Add 1.452 to 1.3


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Line the decimals up: 1.452 + 1.3

"Pad" with zeros: 1.452 +1.300Add: 1.452 + 1.300

2.752

Example: Add 1.452 to 1.3Example: Add 1.452 to 1.3


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Hope you guys have a greatHope you guys have a great

time learning decimals!time learning decimals!

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Let's have fun with Decimals!!