Last year, I posted a comment on Maths Insider, a site about strategies for teaching mathematics to children.  My comment has now been republished in a collection of 7 Savvy Ideas from Maths Insider Readers.  There are lots of other helpful ideas there–check it out!

Later, I wrote more about the strategies explained in my comment, as well as 4 other innovative and convenient approaches to arithmetic, in my Arithmetricks article.