Joke Torbeyns, Lieven Verschaffel, Mental computation or standard algorithm? Children's strategy choices on multi-digit subtractions, European Journal of Psychology of Education, Vol. 31, No. 2 (April ...

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. 23 times 7 really just ...