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B1.4 · Read, represent, compare, and order decimals to thousandths

Learn to read, represent, compare, and order decimals to thousandths through clear examples and targeted practice.

Ontario Grade 6 Mathematics

Number

Ontario Grade 6 Mathematics — B1.4

A decimal names a number that may include a part less than one whole. You already know that digits have places, such as ones and tenths. This lesson adds hundredths and thousandths. A thousandth is one of one thousand equal parts of a whole. You will read, represent, compare, and order decimals with up to three places after the decimal point. All example numbers are made for practice; they are not measurements.

What you will learn

  • Read decimals to thousandths using place-value names.
  • Represent decimals with place value and on a number line.
  • Compare decimals by checking place values from left to right.
  • Order decimals from least to greatest or greatest to least.

1. Read decimals with place value

The decimal point separates the whole-number part from the part less than one. In 4.2864.286, the 44 is in the ones place. After the decimal point, the places are tenths, hundredths, and thousandths, in that order.
A place-value name tells what a digit stands for. In 4.2864.286, the 22 means two tenths, the 88 means eight hundredths, and the 66 means six thousandths. Read the number as four and two hundred eighty-six thousandths.
Zeros can hold places. In 3.0473.047, the 00 shows that there are no tenths. The 44 is in the hundredths place, and the 77 is in the thousandths place. Read this as three and forty-seven thousandths. Keep the zero when writing the number so the other digits stay in their correct places.
A zero at the end of a decimal does not change its value. For example, 0.50.5, 0.500.50, and 0.5000.500 all name five tenths. But a zero between digits can change their places. The numbers 0.5060.506 and 0.560.56 do not have the same value.
0.1=110,0.01=1100,0.001=110000.1=\frac{1}{10},\quad 0.01=\frac{1}{100},\quad 0.001=\frac{1}{1000}
  • The first three places after the decimal point are tenths, hundredths, and thousandths.
  • A zero can hold a place even when it adds no amount.
  • Zeros added or removed at the end of a decimal do not change its value.

2. Represent and compare decimals

You can represent a decimal by naming its places or locating it on a number line. A number line shows numbers in order. Numbers farther to the right are greater. For example, 0.60.6 is to the left of 0.70.7, so 0.60.6 is less than 0.70.7.
To compare two decimals, first compare their whole-number parts. If those are equal, compare the tenths digits. If those are equal too, compare the hundredths digits, then the thousandths digits. Stop at the first place where the digits differ. That place tells which number is greater.
Consider 2.4072.407 and 2.392.39. Their whole-number parts are both 22. Write 2.392.39 as 2.3902.390 to show three decimal places. At the tenths place, the digits are 44 and 33. Since 44 is greater than 33, 2.4072.407 is greater. There is no need to compare later places once the first difference is found.
The symbol << means “is less than.” The symbol >> means “is greater than.” The symbol == means “has the same value as.” For example, 0.62<0.700.62<0.70 says that sixty-two hundredths is less than seven tenths. Writing 0.70.7 as 0.700.70 can make the place values easier to see.
2.407>2.3902.407>2.390
  • Compare from the whole-number part toward the smallest place.
  • The first place where digits differ decides the comparison.
  • Adding zeros at the end can help show matching places without changing value.

3. Order decimals and check

To order decimals, compare them and list them in the direction requested. Least to greatest starts with the smallest number. Greatest to least starts with the largest.
When decimals have different numbers of places, you can add zeros at the ends to show the same number of places. For example, write 1.51.5, 1.081.08, and 1.1251.125 as 1.5001.500, 1.0801.080, and 1.1251.125. The whole-number parts match. The tenths digits show that 1.0801.080 is smallest. Compare the remaining two: at the hundredths place, 1.1251.125 has 22 and 1.5001.500 has 00. Therefore, 1.1251.125 comes next, followed by 1.5001.500.
Check the direction in the question before giving your answer. For least to greatest, each number should be greater than or equal to the number before it. A number line can help you check: the values should move from left to right.
A decimal with fewer than three places still has a value at the thousandths place. For example, 0.8=0.8000.8=0.800. The added zeros show the places clearly; they do not change the number.
1.080<1.125<1.5001.080<1.125<1.500
  • Use matching decimal places when that makes a comparison clearer.
  • For least to greatest, list values from smallest to largest.
  • Check that the order matches the words in the question.

Place-value chart for $2.583$

OnesTenthsHundredthsThousandths
2583

Worked example

Read and represent a decimal

Read 5.0325.032 in words. Identify the value shown by each digit after the decimal point.
Five and thirty-two thousandths
Five and thirty-two thousandthsThe point for $5.032$ is just to the right of $5$ on the line from $5$ to $6$.56+1

The point for $5.032$ is just to the right of $5$ on the line from $5$ to $6$.

  1. Name the places
    Starting just after the decimal point, the places are tenths, hundredths, and thousandths.
    5.0325.032
  2. Read the decimal part
    There are zero tenths, three hundredths, and two thousandths. The zero holds the tenths place, so the 33 stays in the hundredths place.
    0.032=3100+210000.032=\frac{3}{100}+\frac{2}{1000}
  3. Say the number
    Read the whole-number part, then the decimal part using thousandths. The number is five and thirty-two thousandths.
Answer: 5.0325.032 is five and thirty-two thousandths. Its decimal digits show zero tenths, three hundredths, and two thousandths.
Check: The zero is needed. Without it, the 33 would be in the tenths place instead of the hundredths place.

Worked example

Compare two decimals

Which is greater, 0.6080.608 or 0.680.68? Use place value to explain.
Comparing decimals between six tenths and seven tenths
Comparing decimals between six tenths and seven tenthsFrom left to right, the points are $0.6$, $0.608$, $0.68$, and $0.7$.+0.09999999999999998

From left to right, the points are $0.6$, $0.608$, $0.68$, and $0.7$.

  1. Show equal places
    Write 0.680.68 with three decimal places by adding a zero at the end. Its value stays the same.
    0.68=0.6800.68=0.680
  2. Compare from left to right
    The tenths digits both equal 66. At the hundredths place, 00 is less than 88. So 0.6080.608 is less than 0.6800.680.
    0.608<0.6800.608<0.680
Answer: 0.680.68 is greater than 0.6080.608.
Check: On a number line, 0.6080.608 is to the left of 0.6800.680.

Worked example

Order three decimals

Order 3.53.5, 3.0573.057, and 3.4093.409 from least to greatest.
Three decimals in order
Three decimals in orderThe points are shown from least to greatest, moving from left to right.34+1

The points are shown from least to greatest, moving from left to right.

  1. Show thousandths
    Add zeros at the ends where needed. This gives each number three decimal places without changing its value.
    3.500,3.057,3.4093.500,\quad 3.057,\quad 3.409
  2. Compare the numbers
    The whole-number parts are all 33. The tenths digits are 55, 00, and 44. This makes 3.0573.057 the smallest and 3.5003.500 the greatest. The remaining number is 3.4093.409.
    3.057<3.409<3.5003.057<3.409<3.500
  3. Give the requested order
    List the original decimals from least to greatest. The final number may be written as 3.53.5 because it has the same value as 3.5003.500.
Answer: 3.0573.057, 3.4093.409, 3.53.5
Check: The order goes from left to right on a number line. Also, 3.5=3.5003.5=3.500.

Common mistakes and how to avoid them

Thinking that a decimal with more digits must be greater.
Correction: Compare the place values from left to right. For example, 0.6080.608 is less than 0.680.68, even though it has more written digits.
Reading 4.064.06 as four and six tenths.
Correction: The 66 is in the hundredths place. Read 4.064.06 as four and six hundredths. The zero holds the tenths place.
Thinking that adding a zero at the end changes a decimal.
Correction: A zero at the end does not change the value. For example, 0.7=0.70=0.7000.7=0.70=0.700.
Giving an order in the wrong direction.
Correction: Check whether the question asks for least to greatest or greatest to least before listing the numbers.

Lesson summary

  • The first three places after the decimal point are tenths, hundredths, and thousandths.
  • Read each digit by its place. Keep zeros that hold places.
  • Compare from the whole-number part, then move through the decimal places from left to right.
  • Zeros added at the end can show matching places without changing value.
  • Order decimals in the direction the question asks.

Check your understanding

Question 1

Which is greater: 0.4090.409 or 0.410.41?
  1. 0.4090.409
  2. 0.410.41
  3. They are equal
  4. 0.4000.400
Show answer and explanation
0.410.41
Write 0.410.41 as 0.4100.410. Since 0.409<0.4100.409<0.410, 0.410.41 is greater.

Question 2

Which list orders 2.082.08, 2.82.8, and 2.1082.108 from least to greatest?
  1. CAD 2.8, 2.108, 2.08
  2. CAD 2.08, 2.108, 2.8
  3. CAD 2.108, 2.08, 2.8
  4. CAD 2.08, 2.8, 2.108
Show answer and explanation
CAD 2.08, 2.108, 2.8
Write the numbers as 2.0802.080, 2.8002.800, and 2.1082.108. Their order is 2.080<2.108<2.8002.080<2.108<2.800.

Key terms

Decimal point
The mark that separates the whole-number part from the part less than one.
Tenths
The first place to the right of the decimal point. One tenth is one of ten equal parts of a whole.
Hundredths
The second place to the right of the decimal point. One hundredth is one of one hundred equal parts of a whole.
Thousandths
The third place to the right of the decimal point. One thousandth is one of one thousand equal parts of a whole.
Number line
A line that shows numbers in order. Greater numbers are farther to the right.

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Published by DoAssignment. This reviewed lesson follows Ontario Grade 6 Mathematics, expectation B1.4. It is a study resource, not an official curriculum publication.

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