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3.4 Rounding Decimals
Friday, October 1, 2010
For you notebook (copy
this):
For you notebook (copy
this):

Rounding Decimals: to round a decimal to a given
place value, look at the digit in the place to the
right.
For you notebook (copy
this):

Rounding Decimals: to round a decimal to a given
place value, look at the digit in the place to the
right.

    If the digit is 4 or less, round down.
For you notebook (copy
this):

Rounding Decimals: to round a decimal to a given
place value, look at the digit in the place to the
right.

    If the digit is 4 or less, round down.

    If the digit is 5 or greater, round up.
Rounding Decimals with
a number line
Rounding Decimals (write
these examples in your notebook.)
Rounding Decimals (write
these examples in your notebook.)
Round the decimal to the place value of the
bolded digit.
Rounding Decimals (write
these examples in your notebook.)
Round the decimal to the place value of the
bolded digit.

    3.23 ------> 3.2, The digit to the right of 2 is
    3, so round down.
Rounding Decimals (write
these examples in your notebook.)
Round the decimal to the place value of the
bolded digit.

    3.23 ------> 3.2, The digit to the right of 2 is
    3, so round down.

    6.485 ------> 6.49, The digit to the right of 8 is
    5, so round up.
Rounding Decimals (write
these examples in your notebook.)
Round the decimal to the place value of the
bolded digit.

    3.23 ------> 3.2, The digit to the right of 2 is
    3, so round down.

    6.485 ------> 6.49, The digit to the right of 8 is
    5, so round up.

    2.83619 -----> 2. 836, The digit to the right of
    the 6 is 1, so round down.
Rounding Decimals (write
these examples in your notebook.)
Round the decimal to the place value of the
bolded digit.

    3.23 ------> 3.2, The digit to the right of 2 is
    3, so round down.

    6.485 ------> 6.49, The digit to the right of 8 is
    5, so round up.

    2.83619 -----> 2. 836, The digit to the right of
    the 6 is 1, so round down.

    5.961 -----> 6.0, The digit to the right of 9 is 6,
    so round up. This causes the 5 to become a 6.
Now you try:

Round to the decimal as specified:

  5.29 (nearest tenth)

  7.096 (nearest hundredth)

  6.48 (nearest one)

  3.9876 (nearest thousandth)
Check your answers:

Round to the decimal as specified:

  5.29 (nearest tenth)   5.3

  7.096 (nearest hundredth) 7.10

  6.48 (nearest one) 6

  3.9876 (nearest thousandth) 3.988
Write this in your
notebook:

Rounding Small Numbers: You can round a very
small number to the place value of its leading
digit to help make it easier to understand. In a
decimal, the leading digit is the first nonzero digit
as you read from left to right.
Rounding to the Leading Digit (you do
not need to copy this)
Rounding to the Leading Digit (you do
not need to copy this)

A guitar was created that is 0.0003937 inch long. Round the
length of the guitar to the place value of the leading digit.
Rounding to the Leading Digit (you do
not need to copy this)

A guitar was created that is 0.0003937 inch long. Round the
length of the guitar to the place value of the leading digit.

  To Solve: The first nonzero digit as you read 0.0003937
  from left to right is 3 and it is in the ten-thousandths
  place. You should round the digit to the nearest ten
  thousandth.
Rounding to the Leading Digit (you do
not need to copy this)

A guitar was created that is 0.0003937 inch long. Round the
length of the guitar to the place value of the leading digit.

  To Solve: The first nonzero digit as you read 0.0003937
  from left to right is 3 and it is in the ten-thousandths
  place. You should round the digit to the nearest ten
  thousandth.

     Because 9 is to the right of the ten-thousandth’s place,
     round 3 up to 4.
Rounding to the Leading Digit (you do
not need to copy this)

A guitar was created that is 0.0003937 inch long. Round the
length of the guitar to the place value of the leading digit.

  To Solve: The first nonzero digit as you read 0.0003937
  from left to right is 3 and it is in the ten-thousandths
  place. You should round the digit to the nearest ten
  thousandth.

     Because 9 is to the right of the ten-thousandth’s place,
     round 3 up to 4.

     Answer the length rounded to the leading digit is
     0.0004 inch.
Try these (in your notebook)


Round the decimal to the leading digit)

  0.058

  0.0091

  0.0952

  0.006192
Check your answers.


Round the decimal to the leading digit)

  0.058   0.06

  0.0091 0.009

  0.0952 0.10 (you don’t have to have the last 0)

  0.006192 0.006
When you finish this
slideshow:
Take the section quiz (as practice) on
classzone.com. Go to assessments, then click on
section quizzes. Then click on 3.4 Rounding
Decimals.

Then play the animated math game on
classzone.com. Go to animated math. Then click
on Chapter 3: Comparing, Ordering and Rounding
Decimals.

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3.4 rounding decimals

  • 2. For you notebook (copy this):
  • 3. For you notebook (copy this): Rounding Decimals: to round a decimal to a given place value, look at the digit in the place to the right.
  • 4. For you notebook (copy this): Rounding Decimals: to round a decimal to a given place value, look at the digit in the place to the right. If the digit is 4 or less, round down.
  • 5. For you notebook (copy this): Rounding Decimals: to round a decimal to a given place value, look at the digit in the place to the right. If the digit is 4 or less, round down. If the digit is 5 or greater, round up.
  • 7. Rounding Decimals (write these examples in your notebook.)
  • 8. Rounding Decimals (write these examples in your notebook.) Round the decimal to the place value of the bolded digit.
  • 9. Rounding Decimals (write these examples in your notebook.) Round the decimal to the place value of the bolded digit. 3.23 ------> 3.2, The digit to the right of 2 is 3, so round down.
  • 10. Rounding Decimals (write these examples in your notebook.) Round the decimal to the place value of the bolded digit. 3.23 ------> 3.2, The digit to the right of 2 is 3, so round down. 6.485 ------> 6.49, The digit to the right of 8 is 5, so round up.
  • 11. Rounding Decimals (write these examples in your notebook.) Round the decimal to the place value of the bolded digit. 3.23 ------> 3.2, The digit to the right of 2 is 3, so round down. 6.485 ------> 6.49, The digit to the right of 8 is 5, so round up. 2.83619 -----> 2. 836, The digit to the right of the 6 is 1, so round down.
  • 12. Rounding Decimals (write these examples in your notebook.) Round the decimal to the place value of the bolded digit. 3.23 ------> 3.2, The digit to the right of 2 is 3, so round down. 6.485 ------> 6.49, The digit to the right of 8 is 5, so round up. 2.83619 -----> 2. 836, The digit to the right of the 6 is 1, so round down. 5.961 -----> 6.0, The digit to the right of 9 is 6, so round up. This causes the 5 to become a 6.
  • 13. Now you try: Round to the decimal as specified: 5.29 (nearest tenth) 7.096 (nearest hundredth) 6.48 (nearest one) 3.9876 (nearest thousandth)
  • 14. Check your answers: Round to the decimal as specified: 5.29 (nearest tenth) 5.3 7.096 (nearest hundredth) 7.10 6.48 (nearest one) 6 3.9876 (nearest thousandth) 3.988
  • 15. Write this in your notebook: Rounding Small Numbers: You can round a very small number to the place value of its leading digit to help make it easier to understand. In a decimal, the leading digit is the first nonzero digit as you read from left to right.
  • 16.
  • 17. Rounding to the Leading Digit (you do not need to copy this)
  • 18. Rounding to the Leading Digit (you do not need to copy this) A guitar was created that is 0.0003937 inch long. Round the length of the guitar to the place value of the leading digit.
  • 19. Rounding to the Leading Digit (you do not need to copy this) A guitar was created that is 0.0003937 inch long. Round the length of the guitar to the place value of the leading digit. To Solve: The first nonzero digit as you read 0.0003937 from left to right is 3 and it is in the ten-thousandths place. You should round the digit to the nearest ten thousandth.
  • 20. Rounding to the Leading Digit (you do not need to copy this) A guitar was created that is 0.0003937 inch long. Round the length of the guitar to the place value of the leading digit. To Solve: The first nonzero digit as you read 0.0003937 from left to right is 3 and it is in the ten-thousandths place. You should round the digit to the nearest ten thousandth. Because 9 is to the right of the ten-thousandth’s place, round 3 up to 4.
  • 21. Rounding to the Leading Digit (you do not need to copy this) A guitar was created that is 0.0003937 inch long. Round the length of the guitar to the place value of the leading digit. To Solve: The first nonzero digit as you read 0.0003937 from left to right is 3 and it is in the ten-thousandths place. You should round the digit to the nearest ten thousandth. Because 9 is to the right of the ten-thousandth’s place, round 3 up to 4. Answer the length rounded to the leading digit is 0.0004 inch.
  • 22. Try these (in your notebook) Round the decimal to the leading digit) 0.058 0.0091 0.0952 0.006192
  • 23. Check your answers. Round the decimal to the leading digit) 0.058 0.06 0.0091 0.009 0.0952 0.10 (you don’t have to have the last 0) 0.006192 0.006
  • 24. When you finish this slideshow: Take the section quiz (as practice) on classzone.com. Go to assessments, then click on section quizzes. Then click on 3.4 Rounding Decimals. Then play the animated math game on classzone.com. Go to animated math. Then click on Chapter 3: Comparing, Ordering and Rounding Decimals.

Editor's Notes