2 X 2-digit Multiplication

We are currently working hard on learning and practicing the process of multiplying up to 4 digits by 1 digit and 2 digits by 2 digits.  Just learning how to use the “old school” algorithm to solve the problem is no longer enough.  The kids have to be able to explain the process of why that “old school” algorithm works.  I’ve posted short video clips that help to show the multiplication process and what we are expecting the kids to understand and do.  Of course, it is extremely important that the kids learn and memorize their basic multiplication facts!

Multiplication with base ten blocks/area models:

 

“Grid /Window/Box” Method of multiplying 2-digit by 2-digit numbers:

Multiplying with Area Models

Parents,  I’ve given the kids a homework assignment–to teach YOU how to multiply using area models (base-ten blocks).  Unless you are an upper elementary math teacher or you’ve had a 4th grader in the last few years, you most likely have no idea what I’m talking about!  Learning how to use the “old school” algorithm to solve a problem is no longer enough.  The kids have to be able to explain the process of WHY that “old school” algorithm works. Using area models is a way for kids to picture and see what is really happening within a multiplication problem.  Just in case you need some clarification on your child’s “teaching”, here are 2 videos that we used in class.  🙂