Multiply as Whole Numbers, Then Count the Decimal Places
The procedure is the same as whole number multiplication. The challenge is placing the decimal point correctly in the product.
Many children can multiply whole numbers correctly. But when decimal points are added, the same procedure produces errors in decimal point placement. The fix is not reteaching multiplication — it is teaching the decimal placement rule explicitly. "Multiply as whole numbers, then count the total decimal places in both factors. Place the decimal point that many places from the right in the product."
These worksheets build decimal multiplication skills systematically — from decimal × whole number to decimal × decimal with different place values. For students who need whole number multiplication fluency before decimals, see our multiplication practice worksheets.
Three stages — master decimal × whole number first
Worksheets present decimal multiplied by a whole number (3.2 × 4). Multiply as whole numbers (32 × 4 = 128), then count decimal places (1), so answer is 12.8. Spend 5-7 days on this stage.
Worksheets present decimals with the same number of places (2.5 × 1.3). Multiply as whole numbers (25 × 13 = 325), then count decimal places (2 total), so answer is 3.25. Spend 5-7 days on this stage.
Worksheets present decimals with different numbers of places (3.45 × 2.1). Multiply as whole numbers (345 × 21 = 7245), then count decimal places (3 total), so answer is 7.245. Spend 5-7 days on this stage.
Teach this script — count the decimal places
Multiply the numbers as if they were whole numbers. For 3.2 × 1.5, multiply 32 × 15 = 480.
Count how many digits are after the decimal point in each factor. Add them together. For 3.2 (1 decimal) × 1.5 (1 decimal) = 2 decimal places total.
Starting from the right of your product, count left the total number of decimal places. 480 with 2 decimal places becomes 4.80 (or 4.8).
Move decimal 1 place right
3.45 × 10 = 34.5
Move decimal 2 places right
3.45 × 100 = 345
Move decimal 3 places right
3.45 × 1000 = 3450
If your child continues to misplace decimal points despite practice, the issue is usually whole number multiplication fluency or place value understanding. Our Number Sense Foundations course (K-2) builds the conceptual groundwork that makes decimal operations stick. You can also browse all available courses and planners on the resources page.
View Number Sense Foundations — $57Practice adding decimals before multiplication
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Real questions parents ask about decimal multiplication
Our worksheets cover multiplying decimals by whole numbers (3.2 × 4), multiplying decimals by decimals (2.5 × 1.3), multiplying decimals by powers of ten (3.45 × 10, 100, 1000), and real-world word problems involving decimal multiplication.
Multiply as if they were whole numbers, then count the total number of decimal places in both factors. Place the decimal point that many places from the right in the product. For example, 3.2 × 1.5: multiply 32 × 15 = 480. There are 2 decimal places total (one in each factor), so the answer is 4.80 (or 4.8).
The most common decimal multiplication error is placing the decimal point incorrectly. Children often align the decimal points like addition, or guess the placement. The fix is explicit teaching of the rule: "Multiply as whole numbers, then count decimal places." Have your child write the total number of decimal places at the top of the problem before solving. Within 2-3 weeks of explicit practice, most children master the placement rule.
The procedure is the same, but decimal point placement is the challenge. For 3.2 × 1.5, multiply as if they were 32 × 15 = 480, then count decimal places (2 total), so answer is 4.80. Children who struggle with this often lack fluency with whole number multiplication or don't understand place value. Our whole number multiplication worksheets provide essential prerequisite practice.
Start multiplying decimals after your child has mastered whole number multiplication (multi-digit) and understands decimal place value. Typically this is in 5th grade. Do not start decimal multiplication until whole number multiplication is automatic — adding decimal points to an already shaky procedure will cause frustration. Most children need 2-3 weeks of whole number multiplication review before starting decimal multiplication.
To multiply a decimal by 10, move the decimal point one place to the right (3.45 × 10 = 34.5). By 100, move two places right (3.45 × 100 = 345). By 1000, move three places right (3.45 × 1000 = 3450). This works because multiplying by 10, 100, or 1000 makes the number larger. Teach this as a shortcut after the standard multiplication method is understood.
15-20 problems per session is effective. Start with decimal × whole number (easier), then decimal × decimal (harder). Spend 2-3 weeks on decimal × whole number before introducing decimal × decimal. Most children need 4-6 weeks total to become fluent with decimal multiplication.
Answer keys provide the final correctly formatted decimal answer. Encourage your child to show their work: write the whole number multiplication, count the decimal places, and place the decimal point. This allows you to see where errors occur.
Generate custom decimal multiplication worksheets. Choose your problem type (decimal × whole number or decimal × decimal) and difficulty level, and download clean PDFs with answer keys.
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