After reviewing Ray's Arithmetic I was inspired to focus on one thing and do it well.
Both my four and six year old are fairly proficient at counting to 100, counting by 10s, and some addition facts. I decided we would focus on a topic that they both needed to work on since I could work with them together, which I always find more fun and engaging.
So, we picked "10." For the last couple weeks, and at least one more to come we have focused on 10. What numbers add up to 10 specifically. Keep in mind the activities that follow were not all from one lesson or even one day. We have varied the application, and gradually moved into different activities over the course of a couple weeks now.
We started by counting to 10. Lining up 10 rocks or shells (taken from our bucket we keep on hand just for math, or maybe art projects if we don't use too many). You can of course use whatever you have around -- coins, dry beans, counting bears, erasers, paperclips, etc.
We counted and rearranged and counted again.
We put them in rows of 2 and then rows of 5.
I counted by twos with my six year old, and then we moved on to adding and subtracting.
To start with, they each received a set of 10 objects. They would separate them into groups.
We showed all the fact families for 10:
0+ 10 and 10+0
1+9 and 9+1
2+8 and 8+2 (you get the idea) on through
No questions yet, just exploring. Remembering the numbers that go together, learning to recognize which pairs of numbers add up to 10. Memorizing, without really working at it.
While they used the stones, I then wrote the problems on a dry erase board and we said them all together. By this time my six year old had the pairs down pretty consistently and my 4 year old knew about half of them quickly, and could figure the rest out if given a little time. Enough mastery that we moved on to the next step.
After they knew how to make 10, we started playing some games with it to reinforce the concepts and stretch their thinking.
Now we went down to just one group of 10 items. I would split this into two groups and hand each child one of the groups.
For example, I would give Nathan 2 and Brooke 8, or Nathan 4 and Brooke 6, or give them both 5, etc.
Then, they had to count how many they had and tell me how many the other person had received. This was a great activity and worked very well. It worked with the two of them because they could both shout out the answer without ruining it for the other person, since they each usually had a different answer that was right, unless they each had five.
If I gave Nathan 2 stones he had to tell me Brooke had 8, while Brooke had to figure out that he had only 2. Make sense? They love this game, and it keeps them on their toes.
This could easily be played with one child as well, and I have with Nathan many times since then. With one child you simply grab a handful of rocks, leaving some (or none) on the table. They must then figure out how many you hold in your hand by counting the rocks left behind on the table.
Of course, you can probably come up with your own variations, and it becomes a new challenge when you move into changing the number of manipulatives you have to begin with.
Giving them something in their hands, and an activity to learn through keeps them engaged in what might otherwise involve boring drill. They have loved this, and have really cemented their math facts this way.
Update: We played another game today that I made up with a deck of cards. I removed the queens and kings and dealt all the cards out. The first person played a card and the second person had to play a card that would add up to 10. Jacks were zero (a carryover from a "Golf" game that we play).
We continued around making combinations of 10 with the cards. Then my kids started getting sneaky and playing more than one card. If I put down a '5' they would put down a 2 and a 3. It is great to see their minds at work!
More Preschool Corner ideas.