Does multiplying decimals seem tricky? It doesn’t have to be! Just like baking your first cake from scratch can feel overwhelming until you learn the recipe, mastering decimal multiplication is easy once you know the steps. Whether you’re a teacher introducing this skill for the first time or a student navigating a decimal unit, understanding a few simple rules will help you succeed with decimal multiplication every time.

Multiplying Decimals Step by Step

Let’s start with the basics—multiplication facts. Knowing your facts or having a handy guide, like a multiplication chart, is essential for mastering decimal multiplication. Even if you know all the steps perfectly, incorrect calculations can lead to the wrong product. So, take your time, use tools that work for you, and build confidence in your math skills. With the right foundation, you’ll be multiplying decimals like a pro in no time.

Think of decimal multiplication as multi-digit multiplication—with a twist. The best part? You can ignore the decimals until the very end. Let’s break it down.

Suppose you’re multiplying 4.56 by 2.8. Start by setting up the equation without worrying about the decimals—treat it like 456×28. This approach simplifies the setup, helping you work efficiently with fewer rows of multiplication.

Here’s a key tip: you don’t need to line up the decimals. In fact, aligning decimals isn’t necessary and might create extra steps, like adding zeros or calculating additional partial products. If lining them up helps you feel confident, go for it—but remember, it’s optional!

Now, let’s complete the multiplication! Ignore the decimals for now and treat it like a regular multi-digit multiplication problem. In this example, 456×28 will result in two partial products:

456×8=3648

456×20=9120

Adding these together gives us 12768.

But we’re not done yet—there’s one last step: placing the decimal. Where does it go when multiplying decimals?

Now that you’ve completed the multiplication, it’s time to place the decimal. Here’s a fun way to remember how to do it:

Add a Symbol: Draw a symbol (like a star, heart, or smiley face) at the very end of the two numbers you multiplied, as well as at the end of the product. This helps connect the numbers and their decimal placement visually.

Count the Decimal Hops:

Start with the first number. For 4.56, count how many hops it takes to move the decimal point to the far right. That’s 2 hops.

 

Do the same with the second number. For 2.8, it’s 1 hop.

 

Add the total hops together: 2+1=3.

 

Hop Backward in the Product: Starting at the symbol in your product (12768), count 3 hops backward and place the decimal point.

Your product becomes 12.768

Following these steps each time you complete (or using this structure to teach) a multiplying decimals equation will ensure your product is always accurate!

Check out this booklet for a printable version of these steps and practice pages to help students move toward multiplying decimals mastery! 

Happy Teaching! 

xo, Kristin @ The Pixie Dust Classroom