I had the opportunity to work with some kindergarteners this week and last. We were working on seeing 5 groups and groups of 10 in numbers.
To start each lesson, I tried some quick choral counting (I read about it at www.tedd.org and heard about it at NCTM in Boston).
On the day for 5 groups, I recorded their counting in rows of 5 under the document camera. Then, I asked what they noticed. They saw "counting by 5s" in the last column, but then they saw "counting by 4 next to it... I said "hmm, let's think about that..." Then we did the rest of the lesson and returned to this at the end. We used counting on to see how much to add to 4 to get 9 and then from 9 to 14.
A week later, I recorded in rows of 10. They noticed lots of repeating numbers. They saw counting by tens in the last column, but didn't see the differences of 10 in the other columns. I chose to use a different color for the noticing on the tens digit in the row for the 30s. I took more time on this day and they noticed even more.
I'd like to try this again with other numbers. It was a quick way to get them all focused and with us with a mathematical goal, too. I'd like to try it with older students, counting by fourths.
Teaching kindergarten is an amazing thing. Teachers have to manage so many things! And stay positive and fun. I tied 3 shoes in half an hour. So much to do! But fun to hear their thinking.