Squaring numbers using the peg board 

This shows how to build the square of 246. units are green, tens are blue, hundreds are red, thousands are green again, ten thousands are blue, and hundred thousands are red. We build the squares and rectangles by filling in the arrays made by the outlines of the quantity. Many of our elementary students at DPM do know how to do this. They love it too! Music to my ears when I hear my students begging to make GIANT squares of numbers. They often make up their own numbers to square.