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How to multiply with multi-digit numbers

This week we are reviewing how to multiply multi-digit numbers using the standard algorithm and/or partial product.  We will start with multiplying 4-digit numbers by a single digit, and then move to multiplying 2-digit by 2-digit numbers.

Some students still do not know all of their multiplication facts.  Please continue to practice these, so their fluency and understanding will increase.

How do I multiply using the standard algorithm?  This is the way that most people multiply.

How do I multiply using partial products?  This is similar to the standard algorithm, but it breaks the factors into expanded form to multiply them, and then adds them back together to get the answer.  For example:

(Since most 5th graders know how to multiply by multi-digit top numbers we only expand the bottom factor. )

28 x 36 would look like this:

28    and    28     then you add the products      840

x 30             x 6      back together -->               +  168

840            168                                                   1008

Click on the LearnZillion picture below to view a video on how to solve multiplication problems using the standard algorithm.

Click on the Youtube link below to view a video on how to solve multiplication probelms using partial products.