Rounding Numbers

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Rounding Numbers
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Rounding Numbers

• ? Sometimes, we dont need a number to be
  completely accurate. In fact, sometimes we
  prefer it to be rounded

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Rounding Numbers

• ? Sometimes, we dont need a number to be
  completely accurate. In fact, sometimes we
  prefer it to be rounded
• Ex) If you asked a friend how far it was to his
  house, how would you feel if he said,

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Rounding Numbers

• ? Sometimes, we dont need a number to be
  completely accurate. In fact, sometimes we
  prefer it to be rounded
• Ex) If you asked a friend how far it was to his
  house, how would you feel if he said,
• Oh, its about 17.62955 kilometres away.

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Rounding Numbers

• ? Sometimes, we dont need a number to be
  completely accurate. In fact, sometimes we
  prefer it to be rounded
• Ex) If you asked a friend how far it was to his
  house, how would you feel if he said,
• Oh, its about 17.62955 kilometres away.
• ? Rounding numbers makes communication easier!

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Rounding Numbers

• ? Ex) Round 16.8722 to the nearest tenth.

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Rounding Numbers

• ? Ex) Round 16.8722 to the nearest tenth.
• Ask, Is that number closer to 16.8 or 16.9
  ?

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Rounding Numbers

• ? Ex) Round 16.8722 to the nearest tenth.
• Ask, Is that number closer to 16.8 or 16.9
  ?
• How do you decide?

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Rounding Numbers

• ? Ex) Round 16.8722 to the nearest tenth.
• Ask, Is that number closer to 16.8 or 16.9
  ?
• How do you know?
• Check the key digit to the right of the tenths
  column.

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Rounding Numbers

• ? Ex) Round 16.8722 to the nearest tenth.
• Ask, Is that number closer to 16.8 or 16.9
  ?
• How do you decide?
• Check the key digit to the right of the tenths
  column.
• THINK Is 87 closer to 80 or 90 ?

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Rounding Numbers

• ? Ex) Round 16.8722 to the nearest tenth.
• Ask, Is that number closer to 16.8 or 16.9
  ?
• How do you decide?
• Check the key digit to the right of the tenths
  column.
• THINK Is 87 closer to 80 or 90 ?
• The number equals 16.9 rounded to the nearest
  tenth.

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Rounding Numbers

• RULE

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Rounding Numbers

• RULE
• Locate the position of the final digit.
• If the key digit is 5 or greater, then round the
  final digit up.
• Otherwise, the final digit stays the same.

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Rounding Numbers

• ? Ex) Complete the following table

Round to the nearest Hundred One Tenth
86 561.99
5 999.64
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Rounding Numbers

• ? Ex) Complete the following table

Round to the nearest Hundred One Tenth
86 561.99 86 600
5 999.64
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Rounding Numbers

• ? Ex) Complete the following table

Round to the nearest Hundred One Tenth
86 561.99 86 600 86 562
5 999.64
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Rounding Numbers

• ? Ex) Complete the following table

Round to the nearest Hundred One Tenth
86 561.99 86 600 86 562 86 562.0
5 999.64
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Rounding Numbers

• ? Ex) Complete the following table

Round to the nearest Hundred One Tenth
86 561.99 86 600 86 562 86 562.0
5 999.64 6 000
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Rounding Numbers

• ? Ex) Complete the following table

Round to the nearest Hundred One Tenth
86 561.99 86 600 86 562 86 562.0
5 999.64 6 000 6 000
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Rounding Numbers

• ? Ex) Complete the following table

Round to the nearest Hundred One Tenth
86 561.99 86 600 86 562 86 562.0
5 999.64 6 000 6 000 5 999.6