Fractions, Decimals, and Percents

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Fractions, Decimals, and Percents
Mr. Swaner
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A Quick Review

• Fractions, decimals, and percents are all parts
  of a whole. They are also related and can be
  converted back and forth.

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0
.25 25
.50 50
0 0
.75 75
1
100
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Decimals

• Decimals are like fractions because they also
  represent parts of a whole, however, decimals use
  the base ten system by place value. The place is
  named by the furthest right number.

tenths, hundredths, thousandths, ten thousandths,
hundred thousandths.
0.1 is said one tenth because the furthest
right number is in the tenth place.
0.17 is said seventeen hundredths for the same
reason,
How would we say 0.83
Eighty-three hundredths
How would we say 0.015?
fifteen thousandths,
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Converting decimals to fractions

• Converting decimals to fractions is easy because
  all we have to do is read the decimal and it
  sounds the same as when we read the fraction.
• We read 0.3 as three tenths. which is
• 0.41 is read forty-one hundredths.

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• .07
• .13
• .3
• .107

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Fractions in base 10

• Fractions in base 10 (denominator 10, 100,
  1000..) are easy because they are also read the
  same way as decimals

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Say it and Write it
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Converting Fractions to Decimals

• If the fraction has a denominator in base ten
  (10, 100, 1,000 etc.) It works the same way.
• is 0.07 both are read seven hundredths.
• If the fraction does not have a base ten
  denominator, you must use long division until you
  get a repeating or terminating decimal.

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Dividing out a Fraction
When dividing the fraction, it is important to
make sure you have the right number in the
house, or inside the division symbol
house
house
basement
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Dividing out a Fraction
When dividing the fraction, it is important to
make sure you have the right number in the
house. or inside the division symbol
house
house
basement
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Lets Try a Few

• Convert 0.49 to a fraction
• Convert .083 to a fraction
• Convert to a decimal
• Convert to a decimal
• Convert to a decimal

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Lets Try a Few

• Convert 0.49 to a fraction
• Convert .083 to a fraction
• Convert to a decimal
• Convert to a decimal

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• I wish I could do this sometimes during the
  summer!

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These are called terminating decimals

• A terminating decimal ends

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A Repeating Decimal

• Ummmmmm it repeats. Use a bar to show it repeats

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Day 2?
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Warm Up

• 1) convert 0.16 to a fraction
• 2) convert to a decimal
• 3) convert to a decimal

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Converting Numbers into Percents

• When you have a fraction with a denominator in
  base 10 (10, 100, 1,000), numbers can be easily
  converted into percents.
• The word percent literally means per hundred.
• means you have 40 per hundred or 40
• How could we easily find what percent is?

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Converting Decimals to Percents

• Lucky for us, decimals are ALL in base ten.
• 0.72 means 72 per hundred or 72.
• What happens if we have 0.851
• How many hundredths are there?
• The left over is just a decimal
• An easy rule for converting decimals to percents
  is to simply move the decimal 2 places right.

85
85.1
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Lets Try Some
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Percents to Decimals and Fractions

• To convert a percent to a decimal, we do the
  reverse. Instead of moving the decimal 2 places
  right, we move it 2 places left and drop the
  sign.

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Try One on Your Own
Convert 27 into a decimal
Now convert 0.27 into a fraction
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Closure

• How do you convert a decimal to a fraction?
• How do you convert a fraction to a decimal?
• How do you convert a decimal to a percent?
• How do you convert a percent to a decimal?

Write it as it is read
Long divide
Move the decimal right 2 places
Move the decimal left 2 places