Note I said "will."
My firsties came to me doing SO GREAT in reading, but not-so-great in math. I noticed even my more advanced students struggled with lots of basic concepts, so I have spent the year thus far getting some basic skills and strategies in place, like counting on a number grid, number recognition, addition and subtraction strategies... The list goes on and on.
As soon as we returned from winter break, I gave all my students a guided math assessment to check what they knew. Now, this isn't exactly Common Core aligned... We use Everyday Math, and a lot of the key skills we've learned so far don't necessarily show up in the CCSS. So, it's more so aligned to the first four units in first grade Everyday Math.
Then, I created this spreadsheet (it's a PDF... Leaving it in word messed up formatting bigtime) to track how students did on each component.
Then, I looked at my students' scores, and created a readiness group (in my case, kids who had fewer than 8 points) and an enrichment group (kids with 8 or more points). Within each group, I have groups of four students, or math teams, and each team has a leader. I'll describe these groups more in a later post, as well as what we'll be doing in our groups for mini-lessons, independent work, and math centers.
Hope these documents help! :)