Often, when I call on the children to line up, or to go to their next activity, I'll call the odd numbers first, then the even numbers. (Or even, then odd.)
Sometimes I'll go beyond the number of kids I have in the class so they can really hear the pattern. After a while, they anticipate the pattern I'm calling and are super ready when I get to their number.
Sometimes I'll count by 5s, then go 5s +1, then 5s +2, etc, while pointing the pattern out on our class number grid. (5, 10, 15, 20, 6, 11, 16, 21, 7, 12, etc.)
Other times I'll call a pattern like... 1, 11, 2, 12, 3, 13, and so on. They always watch when I point these out on the number grid as I call out the numbers.
Then there are days I just call out the numbers in order, or in backward order. Sometimes I start with 1, and other times I'll just start with a child who is behaving properly (as opposed to rolling around on the floor, which second graders often see at the end of a lesson!). Then, I've been
known to start with a random number off the top of my head for no reason. I like to keep them on their toes!
Here's another thing I do that helps the children internalize number concepts: I change my jobs after each set of ten! Most teachers change their classroom jobs weekly. I used to do that, but I realized how changing after 10 days will help internalize that concept of ten for these kids, especially since sets of ten is huge in our number system!
Do you have any routines that help secure number concepts? How about reading concepts?