Students will be able to solve multiplication problems with a three-digit factor.
- Explain, "Today we are going learn how to multiply with 3-digit numbers(numbers with a digit in the hundreds place and a value between 100 and 999)."
- Review the value of base ten blocks up to 100s. Hold up a one unit block, ten unit block, and 100 unit block.
Explicit Instruction/Teacher modeling(10 minutes)
- Write a problem on the board, like 4 x 213.
- Draw and display four circles, and using base ten blocks, build a model illustrating four equal groups of 213.
- Remind students that multiplication can be understood as equal groups or repeated addition, no matter the size of the factors.
- Draw a model of the example you built, demonstrating how to draw hundreds, tens, and ones (see example in resources).
- Write a repeated addition sentence to accompany the model (i.e. 213 + 213 + 213 = 852).
Guided practise(15 minutes)
- Hand out the 3-Digit by 1-Digit Multiplication worksheet.
- With the class, draw a model for problem one. Students may need to use scratch paper to draw models.
- Have students work with a partner to draw a model for problem two.
- Instruct students to draw a model for problem three independently, then go over the problem together.
- Review the algorithm (multiply the single-digit factor by each place value of the larger factor). Model an example, like 7 x 649.
- Explain that models help us understand multiplication, but the algorithm can be a more efficient way of finding the product.
- Have students use the algorithm to solve problem four on the worksheet with a partner.
Independent working time(15 minutes)
- Instruct students to solve the remaining problems on the worksheet using the algorithm.
- Circulate and offer support as needed.
- Provide additional examples before assigning independent work.
- For independent work, assign problems with smaller three-digit factors in place of the worksheet.
- Allow students to use a model to solve if needed.
- Assign challenge problems with two-step word problems (see resources).
- Hand out a small piece of scratch paper to each student.
- Write a multiplication problem on the board (i.e. 437 x 3).
- Have students solve using the method of their choice.
- Collect student work as an exit ticket and check for understanding.
Review and closing(8 minutes)
- Show video to review the algorithm if needed (see resources).
- Ask, "Can we use what we learned today to multiply larger factors?"
- Write a 4-digit by 1-digit problem on the board and invite a volunteer to try solving it using the algorithm.
- Ask, "Could we use this algorithm to multiply 5-digit numbers? six-digit numbers?"
- Discuss as a class (i.e. we can use the algorithm to multiply any size factor; the single-digit factor has to be multiplied by each place value in the larger factor no matter how large a number it is).