Multiply 1-digit by 2,3,4-digit number - standard algorithm
I show how to do the standard multiplication algorithm, comparing it to the partial products algorithm (which I'm calling "the easy way" in the video). We do 1 digit by 2 digit, then 1 digit by 3 digits, and also by 4 digits. In several of our practice problems we also estimate the final product before multiplying.
See also
Use mental math (partial products) to multiply
Math Mammoth Grade 4 curriculum