Decimal Notation and Rounding Decimals

1
Decimal Notation and Rounding Decimals

• Chapter 3
• Lessons 1 2

2
What is Decimal Notation?

• Writing numbers using decimal point
• Not whole numbers
• Numbers that are between whole numbers
• Based on parts of a whole - tenths, hundredths,
  and thousandths

3
Every number has a decimal!

• Where is the decimal in a whole number?
• 24
• 24.0
• 112
• 112.0
• 58
• 58.0000000000000000000000000000000
• 1,965
• 1,965.0

4
Correct the decimal mistake!

• John, the fullback on the football team, weighs
  19.5 pounds.
• Marys living room is 200 feet long and 1.2 feet
  wide.
• Mrs. Prozzillo bought 10 gallons of gas for 270.
• Mr. Gurecki paid 185.75 for his new car.
• For Sunday dinner, Mr. Smith bought a turkey that
  weighed .12 pounds.

5
Place Value

• 1.37 Standard Form
• One and thirty seven hundredths Word Form

6
What decimal does the grid represent?

• 0.32
• Thirty two hundredths

7
What decimal does the grid represent?

• 0.7
• Seven tenths

8
What decimal does the grid represent?

• 0.81
• Eighty one hundredths

9
What decimal does the grid represent?

• 2.45
• Two and forty five hundredths

10
Write the number as a decimal

• Fifty-one hundredths
• 0.51
• One and sixty-seven thousandths
• 1.067
• Three and forty-two hundredths
• 3.42
• Five and two tenths
• 5.2

11
Write the decimal in word form

• 0.58
• Fifty eight hundredths
• 9.109
• Nine and one hundred nine thousandths
• 5.4
• Five and four tenths
• 0.013
• Thirteen thousandths

12
Rounding
13
How do you round?

• You will be asked to round to a certain place
  value
• Round 10.674 to the hundredths place
• Box number in place value
• 10.674
• Look at number to the right of the box
• 10.674

14
10.674

• If the number to the right of the box is 5 or
  higher, change the name
• Less than 5 stays the same
• All numbers to the right of the box turn to zeros
• 10.670

15
Round to the given place

• 5.81
• 5.80
• 0.471
• 0.5
• 8.928
• 8.93
• 56.82
• 60
• 52.09
• 52.1

16
Round to the nearest centimeter and to the
nearest tenth of a centimeter

• Round to the nearest centimeter This is the
  whole number
• Round to the nearest tenth of a centimeter -
  decimal

17
Round to the nearest centimeter and to the
nearest tenth of a centimeter

• Round to the nearest centimeter this is the
  whole number
• Round to the nearest tenth of a centimeter -
  decimal