They start with the lines (which I assume is the Singapore model method) in third grade. Up until then it's number bonds. But I bet you can find enough descriptions of it on blogs to introduce the concept yourself.

ETA I just googled "singapore model method" and there are several sites teaching parents how to teach it on the very first page.

Like this
http://www.sleeplessinkl.com/2009/04/24/relearning-maths-using-the-singapore-model-method

Last edited by Tallulah; 01/26/11 03:30 PM.