Math Coach's Corner: Array Models for Multiplication. This little activity is another one from Van de Walle. Students use a 10-by-10 array and an L-shaped overlay to help them visualize the meaning of multiplication.
Love this concept. I still use it to this day when I get a bit confused. Also, the numbers are inverse of themselves. 2x9= 18 9x9=81 Once you get to 45 and 54, you go backwards in reverse from there. I know, confusing, but it can help.