My math notebook is just a cheap spiral notebook (you can get them for a penny in the summer). Each day of the week we do something different.
Monday- Number Talk- There are so many ways to do a number talk. In first grade I try to keep it simple and just look for different ways to make a number. So, I have my kids write "Ways to Make ___" at the top of their page. Then, they think of 7 ways to make the number using addition, subtraction, tallies, money, pictures, etc. After they are finished I will ask a few to share and write them on the board. 
Tuesday- Graphing- I create very simple graphs that fit 2 to a page. Each child gets a page and glues it into the notebook. We do our graph together using their notebooks and the Promethean Board. I go around the room, asking each child the question. We all write the child's class number (easier than their name) in the graph. I ask follow up questions once the graph is complete. I try to keep the graphing questions simple during this time. Any really cute graph, like graphing Skittles or Goldfish, we try to do during our unit time. I like to include as many different types of graphs as possible (tally graph, graphs going up, graphs going sideways, graphs with different amounts of choices).
Wednesday- Estimation- Each week the Star Student (or in my class the Top Banana) brings in items to estimate- usually on Monday just to make sure we have them by Wednesday. Almost everytime they bring in great items...almost. In the past I've estimated rocks, individually wrapped pieces of candy, cotton balls, silly bands, bird feathers, erasers... and Wal-Mart bags all wadded up together (remember the "almost?!!) The kids write "How many (items)?" at the top of their notebook. Then as I walk around with the estimation jar they write down their guess. I go around the room and ask for everyone's guess and record it on the Promethean Board. We come to the carpet and count the objects together- making a focus to count by 2's, 5's, or 10's. Then, we look back to the board and see who came the closest. They children go to their seat, write the correct answer, put a big "star" around it, and then have to write one of the following- "I was too high, I was too low, I was pretty close, I was the closest" We use the Promethean Board to decide who will write each sentence. If the items are edible we eat them during snack time. Sometimes the kids will bring things, like pencils, that they other children can keep. If it's a collectible item I send it home when we're finished. You'll be surprised how much better they get at estimating by the end of the year (my estimating skills have improved tremendously! ha!)
Thursday- Problem Solving- I type up the problems on 2 X 4" labels. I give the kids time to answer the problems then we share strategies together as a class. I will record their answers on the board and discuss why some ways were better than others. The kids are allowed to correct their answers in their notebook and change their thinking if needed. We do many different types of problems throughout the year. Here's my general progression (addition (answer unknown), addition (middle part unknown), subtraction (answer unknown), subtraction (middle part unknow), subtraction (beginning unknown), multiplication (super simple), comparisson, division (just grouping). I use CGI, Cognitively Guided Instruction, during my problem solving time.Friday- I don't formally teach math on Friday. In first grade, Friday is our day of Social Studies/Science Unit study. Of course, there are fabulous math (and reading and writing) ideas to tie in with any unit. So, we are always doing math on Friday. It just doesn't follow the same routines as the rest of the week (no math tubs, no math notebook). This is the time I pull out the cute graph, or we measure a pumpkin and count the seeds, or create a themed glyph, etc.
