---
title: "Multiplying decimals by whole numbers"
description: "Multiply one-digit numbers with up to two decimal places by whole numbers (e.g. 3.47 × 6)"
canonical: https://lightmysky.com/learn/mathematics/multiplying-decimals-by-whole-numbers-mt_SoDP1fSQEB
source: https://lightmysky.com/learn/mathematics/multiplying-decimals-by-whole-numbers-mt_SoDP1fSQEB.md
retrieved: 2026-10-19
---

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# Multiplying decimals by whole numbers

Multiply one-digit numbers with up to two decimal places by whole numbers (e.g. 3.47 × 6)

Subject: Mathematics · Area: Multiplication & Division · Ages 10 to 11
Page: https://lightmysky.com/learn/mathematics/multiplying-decimals-by-whole-numbers-mt_SoDP1fSQEB

## Ready when they can

- Correctly compute 4.56 × 7 using a written method
- Use place-value reasoning to explain why 3.2 × 5 = 16.0
- Model a decimal multiplication using an area diagram or expanded form

## Lesson: Multiplying decimals by whole numbers

Say a bag of sweets costs £1.35 and you want to buy 6 of them for a party. You already know how to do long multiplication with whole numbers. Decimals use the exact same steps, plus one extra move at the end. Multiply the digits as if the decimal point were not even there. Then count how many digits come after the point in the decimal number, and put the point back that many places from the right in your answer.

*(drawing: In 3.47, the point splits the number. Count the digits after it: 4 and 7. That is 2 digits.)*

**Example.** Work out 4.56 × 7. First, multiply as whole numbers: 456 × 7 = 3192. Now count the digits after the point in 4.56: there are 2 (the 5 and the 6). Put the point 2 places from the right in 3192, and you get 31.92.

You can also split the decimal before you multiply. For 3.4 x 2, think (3 x 2) + (0.4 x 2) = 6 + 0.8 = 6.8.

**Tip.** A common slip is lining up the decimal points like you would for adding. Don't do that here. Multiply first, then count the decimal digits in the question to place the point in the answer.

**Recap.** Multiply the digits like whole numbers, then move the decimal point in from the right by the same number of digits that followed the point in the question.

## Practice

18 questions on this page, each with its working shown.

## Needs first

- [Multiplying and dividing (age 10+)](https://lightmysky.com/learn/mathematics/multiplying-and-dividing-age-10-mt_wPgpMJ0-PA)
- [Long multiplication (age 10+)](https://lightmysky.com/learn/mathematics/long-multiplication-age-10-mt_XLP1IM3Qbb)

## Opens up

- [Miles & Kilometres](https://lightmysky.com/learn/mathematics/miles-and-kilometres-mt_3tPI0HqqcN)
- [Calculating percentages](https://lightmysky.com/learn/mathematics/calculating-percentages-mt_PNSyfH56eQ)