Place value is a difficult concept for many kids. Bear has been regularly mixing up places, usually just guessing at whether "41" is fourteen or forty-one. I've tried to help him see the patterns in the hundreds chart, and help him hear that "four" comes before "one" in forty-one, but in the long run he has mostly still been guessing.
Today the math lesson (we are using Horizons kindergarten math) was about place value. I read the teachers manual which said to make a big visual aid showing two columns, and then to put different numbers in them and talk about it... Matching color-coordinated columns were in his workbook. (I do want to note that I have really liked this math curriculum, today is the first time that I have felt like I needed to come up with something additional of my own.)
He has already been learning about pennies and dimes for several weeks. This includes counting them up and writing the total amount of cents (dimes and/or pennies). So, rather than use numbers in the columns demonstration, I used coins. (These happen to be plastic coins from the Horizon's manipulatives set, but obviously real coins would work!)
I made the two columns and labeled and color-coordinated them like his book. Then I got out ten pennies and a few dimes. I made nine spots in the 'ones' place column, so that he could visually see when it was 'filled up.'
Currently he is practicing writing numbers and using number lines up to the 40s, so basically I just counted with him. I put on one penny at a time, and we counted. When we got to nine, I said "uh-oh, I don't have any more places for pennies, I will need to use a dime instead to make the ten cents." I slid all the pennies off the page and put on a dime. I showed him how there was one coin in the first column and zero coins in the second column ("10"). Then we started adding pennies again and counting till we got to 19, when he gleefully swiped the pennies off and plunked down a dime. We continued counting up to 40, and several times I stopped and had him take note of how many coins were in each column, and what number we were on, so that he could see the correlation between place value and numbers.
He seems to get it. ☺
I suspect that somewhere down the road we will revisit this, only adding dollar coins (or dollar bills) to a third column.