5th Grade Multiplying and Dividing Decimals Worksheet Solutions (PDF)

5th Grade math worksheet solutions: Multiplying and Dividing Decimals – Maths PDF


This answer key gives a full worked solution for each of the 20 decimal problems. Each solution shows the whole-number step, the decimal-point step, and the final answer in bold. Compare the steps with your own work to find where a mistake started.

Grade 5 · Common Core State Standards: 5.NBT.B.7

Exercise 1 – Tenths times a whole number

Ignore the decimal points and multiply: \(7 \times 6 = 42\).

The factors have 1 and 0 decimal places, so the product has 1 + 0 = 1 decimal place: \(4.2\).

\(4.2\)

Exercise 2 – Hundredths times a whole number

Ignore the decimal points and multiply: \(6 \times 7 = 42\).

The factors have 2 and 0 decimal places, so the product has 2 + 0 = 2 decimal places: \(0.42\).

\(0.42\)

Exercise 3 – Product from a model

6 columns3 rowsoverlap6 x 3 = 18 squares18 hundredths = 0.18
The overlap holds 18 squares, so the product is 0.18.

6 columns shaded blue show 0.6. 3 rows shaded orange show 0.3.

The overlap is \(6 \times 3 = 18\) squares, and each square is 0.01.

\(0.6 \times 0.3 = 0.18\)

Exercise 4 – Decimal times tenths

Ignore the decimal points and multiply: \(42 \times 5 = 210\).

The factors have 1 and 1 decimal places, so the product has 1 + 1 = 2 decimal places: \(2.10\).

Dropping the extra zero gives \(2.1\).

\(2.1\)

Exercise 5 – Two decimal factors

Ignore the decimal points and multiply: \(36 \times 24 = 864\).

The factors have 1 and 1 decimal places, so the product has 1 + 1 = 2 decimal places: \(8.64\).

\(8.64\)

Exercise 6 – Hundredths and tenths

Ignore the decimal points and multiply: \(25 \times 4 = 100\).

The factors have 2 and 1 decimal places, so the product has 2 + 1 = 3 decimal places: \(0.100\).

Dropping the extra zero gives \(0.1\).

\(0.1\)

Exercise 7 – Zeros in the product

Ignore the decimal points and multiply: \(5 \times 2 = 10\).

The factors have 2 and 1 decimal places, so the product has 2 + 1 = 3 decimal places: \(0.010\).

Dropping the extra zero gives \(0.01\).

\(0.01\)

Exercise 8 – Divide tenths by a whole number

1.21.21.21.24.8
Each part is 1.2.

Divide as with whole numbers: \(48 \div 4 = 12\).

Put the decimal point so the quotient has 1 decimal place: \(1.2\).

\(1.2\)

Exercise 9 – Divide hundredths by a whole number

Divide as with whole numbers: \(756 \div 6 = 126\).

Put the decimal point so the quotient has 2 decimal places: \(1.26\).

\(1.26\)

Exercise 10 – Quotient less than 1

Divide as with whole numbers: \(72 \div 9 = 8\).

Put the decimal point so the quotient has 2 decimal places: \(0.08\).

\(0.08\)

Exercise 11 – Keep dividing with zeros

Write 9.3 as 9.30 so the division can end.

Divide as with whole numbers: \(930 \div 5 = 186\).

Put the decimal point so the quotient has 2 decimal places: \(1.86\).

\(1.86\)

Exercise 12 – Divide by tenths

6.3 / 0.9x 10 both63 / 9divide7
Both numbers are multiplied by 10.

Multiply both numbers by 10 so the divisor is a whole number: \(6.3 \times 10 = 63\) and \(0.9 \times 10 = 9\).

Now divide: \(63 \div 9 = 7\).

\(7\)

Exercise 13 – Divide by hundredths

Multiply both numbers by 100 so the divisor is a whole number: \(1.44 \times 100 = 144\) and \(0.12 \times 100 = 12\).

Now divide: \(144 \div 12 = 12\).

\(12\)

Exercise 14 – Decimal divided by decimal

Multiply both numbers by 10 so the divisor is a whole number: \(0.72 \times 10 = 7.2\) and \(0.4 \times 10 = 4\).

Now divide: \(7.2 \div 4 = 1.8\).

\(1.8\)

Exercise 15 – Apples at the market

Multiply the weight by the price per pound: \(3.5 \times 1.8\).

Ignore the decimal points and multiply: \(35 \times 18 = 630\).

The factors have 1 and 1 decimal places, so the product has 1 + 1 = 2 decimal places: \(6.30\).

Dropping the extra zero gives \(6.3\).

The product 6.3 means $6.30.

The apples cost $6.30.

Exercise 16 – Ribbon for bows

Ribbon used: \(0.65 \times 12\).

\(65 \times 12 = 780\), and 2 decimal places gives \(7.80 = 7.8\).

Ribbon left: \(10 – 7.8 = 2.2\).

2.2 yards are left.

Exercise 17 – Unit price

Divide the total cost by the number of pounds: \(14.40 \div 1.8\).

Multiply both numbers by 10 so the divisor is a whole number: \(14.40 \times 10 = 144\) and \(1.8 \times 10 = 18\).

Now divide: \(144 \div 18 = 8\).

Trail mix costs $8 per pound, or $8.00.

Exercise 18 – Movie tickets

Total cost: \(8.75 \times 4\).

\(875 \times 4 = 3{,}500\), and 2 decimal places gives \(35.00\).

She pays $40. Change: \(40 – 35 = 5\).

Priya gets $5.00 in change.

Exercise 19 – Trail markers

Divide the trail length by the length of one section: \(5.4 \div 0.45\).

Multiply both numbers by 100 so the divisor is a whole number: \(5.4 \times 100 = 540\) and \(0.45 \times 100 = 45\).

Now divide: \(540 \div 45 = 12\).

The trail has 12 equal sections.

Exercise 20 – Garden soil

Area: \(3.6 \times 2.5\).

\(36 \times 25 = 900\), and 2 decimal places gives \(9.00 = 9\) square feet.

Cost: \(9 \times 0.75\).

\(9 \times 75 = 675\), and 2 decimal places gives \(6.75\).

The area is 9 square feet and the soil costs $6.75.

All Grade 5 chapters: Grade 5 math.

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