Multiplying Decimals
Easily Explained w/ 7 Examples!

How to multiply decimals?

Jenn, Founder Calcworkshop^®, 15+ Years Experience (Licensed & Certified Teacher)

It’s just 3 simple steps that’ll you learn in today’s math lesson.

Let’s go!

Multiply decimals is like multiplying whole numbers, except the only difference is that we need to keep track of our decimal places.

Vocabulary

But first, let’s start with some vocabulary and notation.

Factors In Multiplication

This means that when we multiply two decimal numbers together, we are still just multiplying two factors.

And how do we indicate multiplication?

When multiplication was first introduced to us, we always used the “x” symbol to indicate multiplication. But as we progress toward Algebra, we will need to add a raised dot and parentheses to our notation.

Symbols For Multiplication

How To Multiply Decimals Step By Step

So, now that we know our vocabulary and our notation, how do we multiply decimals?

With three easy steps:

First, we write each factor vertically, placing the number with the most digits on top, lining up the last digits on the right and ignoring the decimal points.


Written Multiplication

Next, we count the decimal places in the factors and rewrite the problem without decimals. The number of decimal places indicates the location of the decimal point in the product.


Counting Decimal Places

1. Finally, we multiply the factors together and put our decimal point back in. We do this by starting from the last digit, and counting left the number of places we found in step two as noted by Math.com


How To Place The Decimal In The Product



Multiplication With One Decimal

That’s all there is to it.

Now what you will notice, as you progress through math grades, is that each grade digs a little deeper into the topic of decimal multiplication.

4th & 5th Grade Decimals

So, in the fourth and fifth grades, you will multiply either two, one-digit, or two-digit decimal numbers. For example, suppose we wanted to find the product of 7.3 and 2.

Multiplying Decimals By Whole Numbers

6th & 7th Grade Decimals

And in sixth and seventh grade you will be multiplying multi-digit decimal values, such as finding the product of 34.12 and 0.2003.

Multi Digit Multiplication

But as you will quickly see in this video, it really doesn’t matter how many numbers or how many decimal places there are, because the technique is always the same.

Words For Multiplying

And it’s always important to remember some keywords the remind us that we want to multiply, such as:

• Product
• Times
• Multiplied by
• Of
• Each
• Twice
• Triple

Worksheet (PDF) — Hands on Practice

Easy to follow worksheets with detailed answers.

Practice Problems
Step-by-Step Solutions

This video will walk you through all the ins and outs of how to multiply decimals, and even look at some keywords and phrases that indicate multiplication as the list above nicely indicates. This way, whenever we seem them in a word problem in future lessons, we’ll know exactly what to do.

Let’s get to it!

Multiplying Decimals – Lesson & Examples (Video)

26 min

• Introduction to Video: Multiplying Decimals
• 00:00:29 – How do we multiply decimals? What symbols represent multiplication?

• 00:05:36 – Find the product (Example #1)
• 00:08:17 – Multiply the decimals (Examples #2-5)
• 00:18:03 – Determine the product (Examples #6-7)
• 00:23:05 – What are the key words that tell us to “multiply”?
• Practice Problems with Step-by-Step Solutions
• Chapter Tests with Video Solutions