course 1 3-1 representing, comparing, and ordering decimals 3-1 representing, comparing, and...
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Course 1
3-1 Representing, Comparing, and Ordering Decimals3-1
Representing, Comparing, and Ordering Decimals
Course 1
Warm UpWarm Up
Lesson PresentationLesson Presentation
Problem of the DayProblem of the Day
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Warm UpOrder the numbers from least to greatest.
1. 242, 156, 224, 165
2. 941, 148, 914, 814, 721
3. 345, 376, 354, 397
156, 165, 224, 242
148, 721, 814, 914, 941
345, 354, 376, 397
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Problem of the Day
Lupe is taller than Reba and shorter than Miguel. Tory is shorter than Lupe but taller than Reba. List the four brothers and sisters in order from tallest to shortest.
Miguel, Lupe, Tory, Reba
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Put these decimals in order from largest to smallest. Come up with a rule for ordering.
8.008 8 8.8 8.07 88.1 8.088
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Additional Example 1: Reading and Writing Decimals
Write each decimal in standard form, expanded form, and words.
A. 1.07
B. 0.03 + 0.006 + 0.0009
1 + 0.07Expanded form:
one and seven hundredthsWord form:
0.0369Standard form:
three hundred sixty-nine ten-thousandthsWord form:
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Additional Example 1: Reading and Writing Decimals
Write the decimal in standard form and expanded form.
C. fourteen and eight hundredths
14.08Standard form:
10 + 4 + 0.08Expanded form:
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Check It Out: Example 1
Write each decimal in standard form, expanded form, and words.
A. 1.12
B. 0.6 + 0.008 + 0.0007
1 + 0.1 + 0.02Expanded form:
one and twelve hundredthsWord form:
0.6087Standard form:
six thousand eighty-seven ten-thousandthsWord form:
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Check It Out: Example 1
Write each decimal in standard form and expanded form.
C. eleven and two hundredths
11.02Standard form:
10 + 1 + 0.02Expanded form:
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Additional Example 2: Earth Science Application
The star Wolf 359 has an apparent magnitude of 13.5. Suppose another star has an apparent magnitude of 13.05. Which star has the smaller magnitude?
13.50 Line up the decimal points.
Start from the left and compare the digits.
13.05 Look for the first place where the digits are different.
0 is less than 5.
13.05 < 13.50
The star that has an apparent magnitude of 13.05 has the smaller magnitude.
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Check It Out: Example 2
Tina reported on a star for her science project that has a magnitude of 11.3. Maven reported on another star that has a magnitude of 11.03. Which star has the smaller magnitude?
11.30 Line up the decimal points.
Start from the left and compare the digits.
11.03 Look for the first place where the digits are different.
0 is less than 3.
11.03 < 11.30
The star that has a magnitude of 11.03 has the smaller magnitude.
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Additional Example 3: Comparing and Ordering Decimals
Order the decimals from least to greatest.
16.67, 16.6, 16.07
16.67
16.60
Compare two of the numbers at a time.
Write 16.6 as “16.60.”16.60 < 16.67
16.67
16.07Start at the left and compare the digits.16.07 < 16.67
16.60
16.07Look for the first place where the digits are different.16.07 < 16.60
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Additional Example 3 Continued
Graph the numbers on a number line.
16.6716.07 16.6
16 16.1 16.2 16.3 16.4 16.5 16.6 16.7 16.8 16.9 17
The numbers are ordered when you read the number line from left to right. The numbers in order from least to greatest are 16.07, 16.6, and 16.67.
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Check It Out: Example 3
Order the decimals from least to greatest.
12.42, 12.4, 12.02
12.42
12.40
Compare two of the numbers at a time.
Write 12.4 as “12.40.”12.40 < 12.42
12.42
12.02Start at the left and compare the digits.12.02 < 12.42
12.40
12.02Look for the first place where the digits are different.12.02 < 12.40
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Check It Out: Example 3 Continued
Graph the numbers on a number line.
12.4212.02 12.4
12 12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 13
The numbers are ordered when you read the number line from left to right. The numbers in order from least to greatest are 12.02, 12.4, and 12.42.
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Lesson Quiz: Part I
Write each in standard form, expanded form and words.
1. 8.0342
2. 10 + 8 + 0.3 + 0.006
3. eight and twelve hundredths
18.306; eighteen and three hundred six thousandths
8 + 0.03 + 0.004 + 0.0002; eight and three hundred forty-two ten thousandths
8.12; 8 + 0.1 + 0.02
Course 1
3-1 Representing, Comparing, and Ordering Decimals
Lesson Quiz: Part II
4. It takes Pluto 246.7 years to orbit the Sun, and it
takes Neptune 164.8 years. Which planet takes
longer to orbit the Sun?
5. Order the decimals from least to greatest: 16.35,
16.3, 16.5.
Pluto
16.3, 16.35, 16.5