More Blocks & Constructs = Night 2

Little sis missed big sis's discovery from the night before. She discovered and proved her understanding of square numbers to me in case you missed it. She's 4.

So last night, I asked big sis to show her little sis a square number. She eagerly got to work demonstrating her understanding of what a square number represents.

I did not say a word. I just folded laundry and watched while they explored. One of the original squares big sis built to explain was made with two rows of blue and one of green.
Little sis started building on big sis's blue and green square. First she stretched the pattern into a rectangle. Then, she instructed her sister, "Close your eyes." She quickly build the rest of the square.

"I made a really big one," she giggled.

After little sis made her great square, she said, "Open your eyes." Her big sister did and she counted the giant square.  Big sis declared 25 is a square number.