And it is the one time that markers are typically used in a Montessori class - if the dot game is kept in a glass frame or laminated and mounted - the children can use a dry erase marker and eraser and use it again and again!
Legoboy did it at school, and wanted it to do it at home (that year I alternated subbing at Montessori schools and working at home - and homeschooling - it was a crazy, but wonderful year!) --- well, I just printed it out and he filled it in. We downloaded this version from Montessori Materials - a great place for some of the printable materials.
Then I had to print more - because he just ate it up!
Here is his first one... It's so pretty! I wrote the first set of numbers and everything else was on him.
- doing the work ALL on paper, in typical addition format (on the right side) --- but connecting it back to their previous work of no more than 9 in any category!
- introduction of the comma. Until this time they have not really been using the comma. There are many adults (ahem, me) who try to sneak that comma in there sooner - before the child is ready (too many new things at once if it is introduced sooner!) and most of the time the adult doesn't even realize he or she is doing it! It's so instinctive! But we want the children to focus on place value, so we don't worry about the comma until around this time - this is close to the time they will also learn about millions with the wooden hierarchical material - so the next step is to be introduced to the repetition of the categories (unit, ten, hundred; unit of thousand, ten of thousand, hundred of thousand, etc.).