Addition Algorithm--Partial Sums http://www.dallassd.com/resources/Parent%20Resources/PartialSums.htm
Subtraction Algorithm--Partial Differences http://www.dallassd.com/resources/Parent%20Resources/PartialDifferences.htm
Multiplication Algorithm--Partial Products http://www.dallassd.com/resources/Parent%20Resources/PartialProducts.htm
Multiplication Algorithm--Lattice Method http://www.dallassd.com/resources/Parent%20Resources/Lattice.htm
Division Algorithm--Subtractive Method http://www.dallassd.com/resources/Parent%20Resources/DivisionSubtmethod.htm
Division Algorithm--Subtractive Method (Involving Decimals) http://www.dallassd.com/resources/Parent%20Resources/DivisionSubtmethodwdecimals.htm
Third Grade Content http://everydaymath.uchicago.edu/educators/3rdgradecontent.shtml