Begin with twenty-three
Two tens and three units represent twenty-three. Exchange one ten for ten units. One ten and thirteen units still represent twenty-three.
Keep the scale honest
A rod contains ten unit lengths. A hundred flat contains ten rods; a thousand cube contains ten flats. Correct proportions help explain the base-ten structure.
Follow the same quantity
Compare the inventory, diagram and notation after each exchange. A camera movement changes the view, while an exchange changes the arrangement of pieces.
Try the relationship.
The activity is a way to inspect an idea. Keep its learning aim and assumptions visible as you change the representation.
Open the related experienceSources and further reading
An original website editorial explanation with fictional teaching examples. It is not a quotation or article authored by Dr Sako.