When we were first introducing the concept of muliplication, we discovered that using the various LEGO sizes showed the "row x column" concept better than any workbook. For example, we'd say, "Can you please find the 4 x 2 block? Look at how there are 4 rows of studs (across) and 2 columns (down). 4 rows of 2 = 8, so this 4x2 block has 8 studs. Let's count the studs; yup, there are 8!" The light went on very quickly since DS loves LEGOS and he had a reason to discern between the 4-peg/6-peg/8-peg pieces. It only took 1 lesson, but muliplying was a cinch for him after that.
