2- and 3-Digit Multiplication

Lesson Plan - Get It!

Audio:

Multiplying multi-digit numbers is similar to multiplying single-digit numbers, except a few more steps are involved.

The following video will walk you through the steps of multiplying a multi-digit number by another multi-digit number. As you watch, write down the answers to the following questions.

• How is multiplying a single-digit number on the bottom different from having a multi-digit number on the bottom?
• What important step needs to be remembered when moving to the second line of multiplication?

When multiplying a two- or three-digit number by a two-digit number, start multiplying in the ones place, then move to the tens place.

Look at how to set up and solve the problem from the beginning of the lesson.

The bakery sells 22 donuts in a box.

• If Sandra buys 12 boxes of donuts, how many donuts will she have?

The multiplication problem is 22 x 12 because each box contains 22 donuts. Instead of adding 22 to itself 12 times, multiply. The order of the numbers in multiplication doesn’t matter.

Step 1

Write the problem and line up the digits.

Step 2

Multiply the digit in the ones place of the bottom number by both digits in the top number.

Step 3

Move to the tens place to begin multiplying that digit by the digits in the top numbers. Since you are now multiplying numbers in the tens place, you must add a placeholder of zero (0) to represent this.

Step 4

Multiply the number in the tens place of the bottom number by both digits of the top number. Notice how the numbers in the answer are moved down a row and shifted to the left because of the placeholder zero.

Step 5

Add up the two products below the original problem. In this problem, add 44 + 220 =, which is 264. There are 264 donuts in 12 boxes.

The steps are similar When multiplying larger numbers, such as a three-digit number, by a two-digit number.

Example: 526 x 52 =

Step 1

Write the digits so that the ones, tens, and hundreds of spots are lined up. Since the number 52 has no digit in the hundreds place, it is left blank.

Although the numbers can be written in any order, the number with more digits is usually on top.

Step 2

Multiply the bottom digit in the ones place by each digit in the top number. You need to regroup if a number is larger than 9 in any place value spot.

Step 3

Multiply the bottom digit in the tens place by each digit in the top number. Don’t forget to add the placeholder zero!

Step 4

Add the products together to get the final answer: 526 x 52 = 27,352.

Consider these questions.

• When setting up a multiplication problem, which number is written on the top?
• How do you know if you need to regroup when multiplying?

In the Got It? section, practice multiplying two- and three-digit numbers with interactive practice.