Seeing Spots and Developing Multiplicative Sense Making
Cans on a grocery store shelf and Hirst's Capric Acid Amide can illustrate dot arrays, thus helping students understand the distributive property, partial products, and the standard algorithm for multiplication.
Matney, Gabriel T. and Daugherty, Brooke N., "Seeing Spots and Developing Multiplicative Sense Making" (2013). Teaching and Learning Faculty Publications. 3.
Mathematics Teaching in the Middle School
National Council of Teachers of Mathematics