So when it comes to measuring the efficiency of a multiplication algorithm, it’s the small multiplications that concern us most. Let’s revisit our example, 25 × 63, with efficiency in mind. In order ...

That and even faster algorithms are mentioned in the video, including David Harvey and Joris van der Hoeven’s O(n log n) algorithm which is only faster for numbers having more than 2^(1729^12) bits.

Screenshot Via YouTube While the box method is essentially the same as the standard algorithm, it does a much nicer job of illustrating what's going on in a multiple-digit multiplication problem ...

Practise dividing a 2-digit number by a 1-digit number using different methods (no remainder). Multiplication as scaling Learn how to understand and use multiplication as scaling.