How to Multiply One-Digit by Three-Digit Numbers

In the last lesson, you learned how to multiply 1-digit numbers by 2-digit numbers, like these:

98 × 3 = ?

You used the column method:

Now, you're ready to multiply even bigger numbers.

Multiplying One-Digit by Three-Digit Numbers

Let's learn with an example.

431 × 3 = ?

First, we write the numbers in column form, starting with the bigger number.

Now, let's multiply each digit of the top number by the bottom number, one at a time.

Let's start with the Ones digits.

Next, let's multiply the digit at the Tens place.

Finally, multiply the digit at the Hundreds place.

So our answer is 1,293.

You did it. 🤗 Great job.

Let's try one more example.

708 × 9 = ?

Let's follow the steps again.

First, write the numbers in column form like this:

Now, let's multiply each digit of the top number by the bottom number.

First, let's multiply the digit at the Ones place.

Because 8 times 9 is a two-digit number, we have a carry over.

Next, we multiply the digit at the Tens place, and add the previous carry.

Remember: 0 multiplied by any number is 0 itself.

So, 0 × 9 = 0.

Add the carry, and we get 0 + 7 = 7.

Finally, we multiply the digit at the Hundreds place.

Our answer is 6,372.

Nice work. 😸

Let's try one more example.

5 × 623 = ?

Follow the steps again.

First, write the numbers in column form. ✅ 

Now, multiply each digit in the top number by the bottom digit. ✅ 

First, multiply the digit at the Ones place (and move the carry to the next place value).

Next, we multiply the digit at the Tens place, and add the previous carry.

Lastly, we multiply the digit at the Hundreds place, and add the previous carry.

What answer did you get?

Yest! 👍 It's 3,115.

Awesome.

Think you got it? Try the practice.