Dividing decimals

Here you will learn about dividing decimals, including how to divide decimals by a whole number, divide decimals by decimals, and divide whole numbers by a decimals. You will learn how to use decimal division to solve word problems.

Students will first learn about dividing decimals as part of their work in number and operations in base ten in fifth grade.

What is dividing decimals?

Dividing decimals is when the divisor, dividend and quotient can be a decimal number. Letโ€™s look at strategies for dividing decimals.

Dividing decimal by whole number

Dividing Decimals table image 1
Modeling with a Hundredths Grid

1.1 = 1.10

Dividing Decimals table image 2

Divide into 2 equal groups.

Dividing Decimals table image 3

55 squares in each group so the quotient is \textbf{0.55.}

Using the Algorithm

Dividing Decimals table image 4

โ— Make sure the divisor is a whole number.
โ— Line up decimal point.
โ— Use 0' s as place holders as necessary.
โ— Do long division

Quotient \textbf{= 0.55}

Dividing decimal by a decimal

Dividing Decimals table image 5
Modeling with a Hundredths Grid

How many groups of 0.2 are there in 1.1?

Dividing Decimals table image 6

You can see there are 5.5 groups so the quotient is \textbf{5.5.}

* \cfrac{1}{2} = 0.5

Using the Algorithm

Dividing Decimals table image 7

โ— Check the divisor, if itโ€™s a whole number start dividing.
โ— If the divisor isnโ€™t a whole number, decide what power
of 10 to multiply by that will make it a whole number.
โ— Multiply dividend by the same power of ten you
multiplied the divisor by.
โ— Line up decimal point of dividend with the
quotient, add necessary 0โ€™ s as place holders.
โ— Do long division

Quotient \textbf{= 5.5}

Dividing a whole number by a decimal

Dividing Decimals table image 8

How many groups of 0.2 \; (0.20) are there in 11?

Dividing Decimals table image 9

You can see there are 55 groups so the quotient is \textbf{55.}

Using the Algorithm

Dividing Decimals table image 10

โ— Check the divisor, if itโ€™s a whole number start dividing.
โ— If the divisor isnโ€™t a whole number, decide what power
of 10 to multiply by that will make it a whole number.
โ— Multiply dividend by the same power of ten you
multiplied the divisor by.
โ— Line up decimal point of dividend with the
quotient, add necessary 0โ€™ s as place holders.
โ— Do long division

Quotient \textbf{= 55}

What is dividing decimals?

What is dividing decimals?

Common Core State Standards

How does this relate to 5th grade math and 6th grade math?

  • Grade 5: Number & Operations Base Ten (5.NBT.B.7)
    Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.

  • Grade 6: The Number System (6.NS.B.3)
    Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each operation.

How to divide decimals

In order to divide decimals using the algorithm:

  1. If the divisor is a whole number, go to step 3. If not, decide the power of ten that will make the divisor a whole number.
  2. Multiply both the divisor and the dividend by the same power of \bf{10} .
  3. If the dividend is a decimal number, line up the decimal point of the dividend with the decimal point of the quotient. You may need to include zeros as place holders.
  4. Do long division.

In order to solve real world problems using decimal division:

  1. Read the problem, identify keywords, and decide which number is the dividend and which number is the divisor.
  2. If the divisor is a whole number, go to step 4. If not, decide the power of ten that will make the divisor a whole number.
  3. Multiply both the divisor and the dividend by the same power of \bf{10} .
  4. If the dividend is a decimal number, line up the decimal point of the dividend with the decimal point of the quotient. You may need to include zeros as place holders.
  5. Do long division.
  6. Label your answer appropriately.

[FREE] Dividing Decimals Worksheet (Grade 5 and 6)

[FREE] Dividing Decimals Worksheet (Grade 5 and 6)

[FREE] Dividing Decimals Worksheet (Grade 5 and 6)

Use this worksheet to check your 5th grade and 6th grade studentsโ€™ understanding of dividing decimals. 15 questions with answers to identify areas of strength and support!

DOWNLOAD FREE
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[FREE] Dividing Decimals Worksheet (Grade 5 and 6)

[FREE] Dividing Decimals Worksheet (Grade 5 and 6)

[FREE] Dividing Decimals Worksheet (Grade 5 and 6)

Use this worksheet to check your 5th grade and 6th grade studentsโ€™ understanding of dividing decimals. 15 questions with answers to identify areas of strength and support!

DOWNLOAD FREE

Dividing decimals examples

Example 1: dividing a decimal by a whole number using the algorithm

Solve the decimal division problem.

0.16 \div 4 = \; ?

  1. If the divisor is a whole number, go to step 3. If not, decide the power of ten that will make the divisor a whole number.

The divisor is 4 which is a whole number.

3If the dividend is a decimal number, line up the decimal point of the dividend with the decimal point of the quotient. You may need to include zeros as place holders.

Dividing Decimals image 5 US

4Do long division.

Dividing Decimals image 6 US

The answer makes sense because on the hundredths grid it shows the quotient to be 0.04. The 4 equal groups have 4 squares. 4 squares = \; 0.04

Dividing Decimals image 7 US

Example 2: dividing a decimal by a decimal using algorithm

Solve the decimal division problem.

32.85 \div 0.9 = \; ?

If the divisor is a whole number, go to step 3. If not, decide the power of ten that will make the divisor a whole number.

Multiply both the divisor and the dividend by the same power of \bf{10} .

If the dividend is a decimal number, line up the decimal point and place it on decimal. You may need to add zeros as place holders.

Do long division.

Example 3: dividing a whole number by a decimal using algorithm

Solve the decimal division problem.

77 \div 0.35 = \; ?

If the divisor is a whole number, go to step 3. If not, decide the power of ten that will make the divisor a whole number.

Multiply both the divisor and the dividend by the same power of \bf{10} .

If the dividend is a decimal number, line up the decimal point and place it on decimal. You may need to add zeros as place holders.

Do long division.

Example 4: decimal division word problem

Carly has 26 meters of rope that she wants to cut into equal pieces that are 0.4 meters in length. How many pieces can she cut?

Read the problem, identify keywords, and decide which number is the dividend and which number is the divisor.

If the divisor is a whole number, go to step 4. If not, decide the power of ten that will make the divisor a whole number.

Multiply both the divisor and the dividend by the same power of \bf{10} .

If the dividend is a decimal number, line up the decimal point of the dividend with the decimal point of the quotient. You may need to include zeros as place holders.

Do long division.

Label your answer appropriately.

Example 5: decimal division word problem

Julia and her sister are making holiday cookies. They have 0.384 ounces of red food coloring that they want to divide equally into 4 bowls of cookie dough. How much food coloring should there be in each bowl?

Read the problem, identify keywords, and decide which number is the dividend and which number is the divisor.

If the divisor is a whole number, go to step 4. If not, decide the power of ten that will make the divisor a whole number.

If the dividend is a decimal number, line up the decimal point of the dividend with the decimal point of the quotient. You may need to include zeros as place holders.

Do long division.

Label your answer appropriately.

Example 6: decimal division word problem

The ice cream sandwiches at school sell for \$1.12. Amelia has \$8.96. How many ice cream sandwiches can she buy?

Read the problem, identify keywords, and decide which number is the dividend and which number is the divisor.

If the divisor is a whole number, go to step 4. If not, decide the power of ten that will make the divisor a whole number.

Multiply both the divisor and the dividend by the same power of \bf{10} .

If the dividend is a decimal number, line up the decimal point of the dividend with the decimal point of the quotient. You may need to include zeros as place holders.

Do long division.

Label your answer appropriately.

Teaching tips for dividing decimals

  • Have students utilize visual models such as hundredths grids or manipulatives such as base ten blocks to build conceptual understanding as opposed to practice worksheets. Division of decimals is a challenging concept for students to master.

  • Have students recall and identify patterns with dividing by powers of 10.

  • Have students use estimation before doing the algorithm so that they can determine if their answer is reasonable.

  • Reinforce place value when dividing.

  • Reinforce the essential academic vocabulary such as dividend, divisor, quotient so that it becomes part of studentsโ€™ everyday math language.

Our favorite mistakes

  • Starting the algorithm of long division with a decimal divisor

  • Forgetting to move the decimal point of the dividend the same number of decimal places as it moved for the divisor
    When multiplying the divisor by a power of ten that will make it a whole number, you have to remember to also multiply the dividend by that same power of ten. In other words, the number of times you move the decimal point in the divisor should be the same as the number of times you move the decimal point in the dividend.

  • Forgetting to align the decimal point of the dividend with the quotient

  • Thinking that the smaller number is always the divisor

  • Confusing the steps of long division

  • Not being mindful of place value by forgetting to include \bf{0} โ€™s as digits for the dividend

Practice dividing decimals questions

1. Solve the decimal division problem.

 

12.82 \div 0.4 = \; ?

3.205
GCSE Quiz False

320.5
GCSE Quiz False

32.05
GCSE Quiz True

32.5
GCSE Quiz False

The divisor is 0.4. Multiply the decimal divisor by 10 to make it a whole number.

 

Also, multiply the dividend by 10.

 

0.4 \times 10 = 4

 

12.82 \times 10 = 128.2

 

Line up the decimal place of the dividend with the decimal place of the quotient.

 

Dividing Decimals image 19 US

 

Use the algorithm of long division to divide.

 

Dividing Decimals image 20 US

2. Solve the decimal division problem.

 

17.43 \div 7 = \; ?

2.49
GCSE Quiz True

24.9
GCSE Quiz False

249
GCSE Quiz False

0.249
GCSE Quiz False

The divisor is 7.

 

Line up the decimal place of the dividend with the decimal place of the quotient. Use the algorithm of long division to divide.

 

Dividing Decimals image 21 US

3. Solve the decimal division problem.

 

105 \div 0.15 = \; ?

70
GCSE Quiz False

7
GCSE Quiz False

7,000
GCSE Quiz False

700
GCSE Quiz True

The divisor is 0.15 which is not a whole number. Multiply the divisor by 100 to make it a whole number. Also, multiply the dividend by 100.

 

This is the same as multiplying by 10^2.

 

Line up the decimal place of the dividend with the decimal place of the quotient.

 

Dividing Decimals image 22 US

 

Use the algorithm of long division to divide.

 

Dividing Decimals image 23 US

4. Solve the decimal division problem.

 

87.22 \div 1.4 = \; ?

62.3
GCSE Quiz True

6.23
GCSE Quiz False

623
GCSE Quiz False

0.623
GCSE Quiz False

The divisor is 1.4. Multiply the decimal divisor by 10 to make it a whole number. Also, multiply the dividend by 10 to make it a whole number.

 

Line up the decimal place of the dividend with the decimal place of the quotient.

 

Dividing Decimals image 24 US

 

Use the algorithm of long division to divide.

 

Dividing Decimals image 25 US

5. Over a three day period, Mila ran a total of 12.36 miles. If she ran the same distance every day, how many miles did she run per day?

4.2 miles

GCSE Quiz False

4.12 miles

GCSE Quiz True

3.12 miles

GCSE Quiz False

4.1 miles

GCSE Quiz False

The divisor is 3 and the dividend is 12.36. The divisor is a whole number. Line up the decimal place of the dividend with the decimal place of the quotient. Use the algorithm of long division to divide.

 

Dividing Decimals image 26 US

6. William baseball card collector. He has saved up \$54.30 to buy the small packs of baseball cards. If each pack of cards cost \$3.62. How many small packs of cards can he buy?

15 small packs

GCSE Quiz True

16 small packs

GCSE Quiz False

14 small packs

GCSE Quiz False

15.5 small packs

GCSE Quiz False

The divisor is 3.62 and the dividend is 54.30. There is a decimal divisor which needs to be multiplied by 100 to make it a whole number. The dividend also needs to be multiplied by 100.

 

3.62 \times 100 = 362

 

54.30 \times 100 = 5,430

 

Dividing Decimals image 27 US

 

Use the algorithm of long division to divide.

 

Dividing Decimals image 28 US

Dividing decimals FAQs:

Can you just move the decimal point of the divisor to make it a whole number?

By multiplying by the appropriate power of ten, you are moving the decimal point. As a shortcut, you can just move the decimal point.

Why do I have to multiply the dividend by the same power of ten as the divisor?

In order to maintain equality, you will have to multiply the dividend by the same power of ten. For example:

1.8 \div 0.2 = 9 is equal to 18 \div 2 = 9
1.8 \div 0.2 = 9 is not equal to 1.8 \div 2 = 0.9

Can you divide a small decimal by a larger decimal?

Yes, the divisor doesnโ€™t have to be smaller than the dividend.

Still stuck?

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