A decimal point is a dot that comes between the whole number places and the decimal places in a numb

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• A decimal point is a dot that comes between the
  whole number places and the decimal places in a
  number. All the digits to the right of the
  decimal point are less than 1 whole. For
  example, 1/10 0.1 one tenth of one whole.

Gr4-U3-L1
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• Decimals are special fractions with unwritten
  denominators of ten, a hundred, a thousand, etc.
  The place of the digits to the right of the
  decimal point in the number tells us what the
  denominator is. The first place to the right of
  the decimal point is the tenths place. For
  example, 1/100.1, and both are called one tenth,
  because the 1 is in the tenths decimal place.

Gr4-U3-L1
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• The first place to the right of the decimal is
  the tenths place and the second place to the
  right of the decimal is the hundredths place.
  For example, 0.1 is one tenth of one whole and
  0.01 is one hundredth of one whole.

Gr4-U3-L2
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• A zero at the right end of a decimal doesnt
  change the amount, but it does change the way it
  is named. A decimal is named by the smallest
  decimal place. For example, this means that 0.1
  is one tenth, and 0.10 is ten hundredths.

Gr4-U3-L2
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• 0.1 and 0.01 are equivalent decimals because they
  name the same amount just as equivalent fractions
  name the same amount.

Gr4-U3-L2
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• Decimals are special fractions with unwritten
  denominators of a ten, a hundred, a thousand,
  etc. A digit in the third place to the right of
  the decimal point is a thousandth. For example,
  0.001 1/1000 one thousandth.

Gr4-U3-L3
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• Our number system is a decimal system because it
  is based on ten, and decem is the Latin word
  for ten. Each place is ten times as big as the
  place to its right.

Gr4-U3-L3
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• When you get ten thousandths, you regroup them as
  one hundredth, when you get ten hundredths, you
  regroup them as one tenth, when you get ten
  tenths, you regroup them as one one, etc.

Gr4-U3-L3
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• Mixed decimals are numbers with a whole number
  and a decimal part. For example, 3.3 grams of
  saturated fat means three whole grams and three
  tenths of a gram more.

Gr4-U3-L4
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• When we say mixed decimal names, we say and
  where the decimal point falls in the number
  because it is a whole number and a decimal part.
  For example, 3.3 grams of saturated fat is read
  as three and three tenths grams of saturated
  fat.

Gr4-U3-L4
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• Numbers increase in size as they move to the
  right on the number line. For example, 6.9 is to
  the right of 5.4 on the number line, so 6.9
  million people is more than 5.4 million people.

Gr4-U3-L4
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• We compare numbers by looking at the digits in
  the largest place first and then comparing the
  digits in each place util we find digits that are
  different. We compare decimals the same way.

Gr4-U3-L5
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• It takes ten hundredths to equal one tenth.
  Decimal tenths are greater than decimal
  hundredths. For example,
• 0.1 gt 0.09.

Gr4-U3-L5
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• Decimal tenths are greater than decimal
  hundredths, and decimal hundredths are greater
  than decimal thousandths. For example, 0.1 gt
  0.09 because tenths are greater than hundredths,
  and 0.01 gt 0.009 because hundredths are greater
  than thousandths.

Gr4-U3-L5
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• 1/2 5/10 0.5, so the decimal 0.5 equals one
  half. 1/2 50/100 0.50, so the decimal 0.50
  equals one half.

Gr4-U3-L6
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• Comparing a decimal to 0, 0.5 (1/2), or 1 helps
  us estimate amounts or interpret data in a
  meaningful way. Remember, a decimal half can be
  written as 0.5, 0.50, 0.500, etc. For example,
  0.525 is close to 0.500, so 8.525 is about 8.5,
  0.08 is about 0 so 2.08 is about 2, and 0.85 is
  about 1 so 3.85 is about 4.

Gr4-U3-L6
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• To round a number we look at the digit to the
  right of the place we want to round to. If it is
  5 or more, we round up. If it is less than 5, we
  round down. We put zeros in the places to the
  right of the place to which we rounded to make
  the number round.

Gr4-U3-L7
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• Rounding works for decimals as well as whole
  numbers because 5 tenths is halfway to one whole,
  5 hundredths is halfway to one tenth, and so on.
  For example, 4.375? 4.38 is 4.375 rounded to the
  nearest hundredth. 4.375? 4.4 is 4.375 rounded to
  the nearest tenth. 4.375? 4 is 4.375 rounded to
  the nearest whole.

Gr4-U3-L7
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• When we round to estimate answers in real life,
  we use flexible rounding. In other words, we
  might round one amount to the nearest tenth and
  another to the nearest one, etc., depending on
  which made the estimate easier to do.

Gr4-U3-L7
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• To add decimal amounts, line the decimal points
  up in a vertical column so that the digits in
  each column are in the same place value. Then
  add as usual.

Gr4-U3-L8
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• To subtract decimal amounts, line the decimal
  points up in a vertical column so that the digits
  in each column are in the same place value. Then
  check each place to regroup if needed and give
  the number a nickname. When all the regrouping
  is done, subtract.

Gr4-U3-L9
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• Understanding decimals is important when solving
  problems with a calculator. For example, if you
  want to add three and five hundredths and twelve
  and four hundred two thousandths, you need to
  under- stand decimals to key in the correct
  amounts, 3.05 12.402, to get the correct sum,
  15.452.

Gr4-U3-L10